All Converters & Calculators
364 free converters and calculators — every one shows the formula it uses, works on any device and gives instant, accurate results.
Temperature converters
Celsius, Fahrenheit, Kelvin and Rankine conversions, body temperature and charts.
- Celsius to FahrenheitConvert °C to °F instantly.
- Celsius to Fahrenheit ChartPrintable °C to °F chart.
- Celsius to Fahrenheit FormulaThe formula explained.
- Fahrenheit to CelsiusConvert degrees Fahrenheit to degrees Celsius.
- Celsius to KelvinConvert degrees Celsius to kelvins.
- Kelvin to CelsiusConvert kelvins to degrees Celsius.
- Fahrenheit to KelvinConvert degrees Fahrenheit to kelvins.
- Kelvin to FahrenheitConvert kelvins to degrees Fahrenheit.
- Fahrenheit to RankineConvert degrees Fahrenheit to degrees Rankine.
- Kelvin to RankineConvert kelvins to degrees Rankine.
- Rankine ConverterConvert any temperature between Rankine, Fahrenheit, Celsius and Kelvin.
- Body Temperature ConverterConvert a thermometer reading between °C and °F and check it against commonly used fever thresholds.
- Fever Temperature ChartUse these charts to read a thermometer in Celsius or Fahrenheit and see whether it shows a fever.
- Fahrenheit to Celsius ChartA printable Fahrenheit to Celsius chart.
- All-in-One Temperature ConverterType a temperature in any scale and instantly see it in all eight: Celsius, Fahrenheit, Kelvin, Rankine, Réaumur, Delisle, Newton and Rømer.
- Réaumur ConverterConvert temperatures between the historical Réaumur scale and Celsius, Fahrenheit and Kelvin — useful for old recipes, cheese making and historical texts.
- Delisle, Newton & Rømer ConverterExplore three historical temperature scales — Delisle, Newton and Rømer — and convert them to and from today’s Celsius, Fahrenheit and Kelvin.
- Temperature Difference Converter (ΔC to ΔF)Convert a temperature change — a rise, drop or difference — between Celsius, Fahrenheit, Kelvin and Rankine.
- Negative Temperature ConverterConvert below-zero temperatures between Celsius and Fahrenheit without sign mistakes, and see where the two scales cross at −40.
- Printable Temperature Table GeneratorMake a custom temperature conversion table for your kitchen, lab or classroom.
- Body Temperature by MethodA “normal” temperature depends on where it is measured.
Time & date calculators
Military time, hours and time cards, durations, days between dates, date math and Unix timestamps.
- Hours to DaysConvert hours to days.
- Days to HoursConvert days to hours.
- Days to WeeksConvert days to weeks.
- Weeks to DaysConvert weeks to days.
- Weeks to MonthsConvert weeks to months (average).
- Months to WeeksConvert months (average) to weeks.
- Military Time ConverterConvert 24-hour military time to standard AM/PM time, or standard time to military time.
- Hours Calculator (Time Card)Add up a week of work hours.
- Time Duration CalculatorFind exactly how much time passes between a start and an end — in days, hours and minutes, and as total hours, minutes or seconds.
- Days Between Dates CalculatorCount how many days there are between two dates — useful for deadlines, countdowns, ages, notice periods and project planning.
- Date CalculatorFind the date a number of days, weeks, months or years before or after any date — for due dates, deadlines, warranties, subscriptions and planning.
- Unix Timestamp ConverterConvert a Unix timestamp to a readable date and time, or a date to a Unix timestamp.
- Minutes to Hours ConverterConvert any number of minutes into hours and minutes, decimal hours (for timesheets) and h:mm clock format.
- Seconds to Minutes ConverterConvert seconds into minutes and seconds, decimal minutes, hours and h:mm:ss clock format — handy for workouts, cooking timers, videos and lap times.
- Time to Decimal Hours ConverterConvert time worked in hours and minutes into decimal hours for timesheets, payroll and invoices.
- Minutes to Decimal ConverterConvert minutes into decimal hours — the format used on timesheets — and see the nearest quarter hour.
- Julian Date ConverterConvert a calendar date to a Julian date — the day-of-year code used on food packaging, in manufacturing and by the military — or decode one back to a date.
- Timecode & Frames ConverterFor video editors: convert timecode to frame counts and real-world time, or frame counts back to timecode.
- BPM to MS ConverterConvert a song’s tempo into delay times in milliseconds for quarter notes, eighth notes, dotted and triplet values.
Math & number converters
Fractions and decimals, inch fractions, Roman numerals, scientific notation, binary, hex and angles.
- Fraction to Decimal ConverterConvert any fraction or mixed number to a decimal and a percentage.
- Decimal to Fraction CalculatorConvert a decimal such as 0.375 or 2.625 into a fraction in lowest terms, plus a mixed number and the closest simple fraction for long or repeating decimals.
- Decimal to Fraction Inches CalculatorTurn decimal inches or millimeters into the nearest fraction of an inch you can find on a tape measure or ruler — to the nearest 1/8, 1/16, 1/32 or 1/64.
- Roman Numeral ConverterConvert any number from 1 to 3,999 into Roman numerals, or read a Roman numeral as a number.
- Scientific Notation ConverterWrite very large or very small numbers in scientific notation, E notation or engineering notation — or convert them back into an ordinary number.
- Binary to Decimal ConverterConvert numbers between binary (base 2) and decimal (base 10), with hexadecimal and octal shown too.
- Hex to Decimal ConverterConvert hexadecimal (base 16) numbers to decimal and back, with binary and octal shown as well.
- Degrees to Radians ConverterConvert angles between degrees and radians.
- Percent to Decimal ConverterConvert between percentages, decimals and fractions — for example 45% = 0.45 = 9/20.
- DMS to Decimal Degrees ConverterConvert map coordinates between degrees, minutes and seconds (40° 26′ 46″ N) and decimal degrees (40.446111) for GPS, Google Maps and GIS.
- Degrees to Percent Slope ConverterConvert a slope between degrees, percent grade and a rise : run ratio — useful for ramps, driveways, roads, roofs and hiking trails.
- Octal ConverterConvert numbers to and from octal (base 8).
- Radians to Degrees ConverterConvert an angle in radians to degrees.
- Online ProtractorEnter an angle to see it drawn on a protractor, along with its type, radians and complementary and supplementary angles.
- Compass Degrees to Direction ConverterTurn a bearing in degrees — from a compass, GPS or wind report — into a compass direction such as SW or NNE.
- How to Convert a Decimal to a FractionChanging a decimal to a fraction takes three steps: write the digits over a power of ten, find the greatest common divisor, and divide.
- Repeating Decimal to Fraction CalculatorEnter the digits before the repeat and the digits that repeat forever.
- Decimal to Fraction ChartA complete decimal to fraction conversion chart.
- Decimal to Fraction WorksheetForty decimal to fraction practice questions in four levels, with an answer key.
Weather calculators
Heat index, wind chill, dew point, humidity and “feels like” temperature.
- inHg to hPa (mb)Convert inches of mercury to hectopascals.
- Heat Index CalculatorThe heat index tells you how hot it really feels when humidity is combined with air temperature.
- Wind Chill CalculatorWind chill is how cold it feels on exposed skin when wind carries body heat away.
- Dew Point CalculatorThe dew point is the temperature at which air becomes saturated and water starts to condense.
- Relative Humidity CalculatorRelative humidity (RH) is the amount of water vapour in the air compared with the most it could hold at that temperature.
- “Feels Like” Temperature CalculatorWeather forecasts show a “feels like” temperature that accounts for wind in cold weather and humidity in hot weather.
- Wind Speed Converter (with Beaufort Scale)Convert a wind speed between every common unit and find its Beaufort force — from calm (0) to hurricane force (12).
- Snow to Rain Ratio CalculatorEstimate how much snow a given amount of precipitation makes, or how much water is in a snowfall, using the air temperature to pick a realistic ratio.
- Wet Bulb Temperature CalculatorThe wet-bulb temperature is the lowest temperature evaporation can cool something to.
- Temperature by Altitude CalculatorEstimate how much colder it is up a mountain or at flight altitude.
- Freezing Point CalculatorEstimate the freezing point of salt water (brine) or an antifreeze and water mix based on its concentration.
- Weather Temperature ChartWhat does a forecast temperature actually feel like? This chart groups outdoor temperatures from extreme cold to extreme heat in °F and °C, with clothing tips.
- Frost & Plant Hardiness Temperature GuideKnow how cold your garden gets.
Cooking & kitchen converters
Oven temperatures, grams to cups, recipe scaling, meat, candy and fridge temperatures.
- Oven Temperature ConverterConvert recipe oven temperatures between °C, °F and UK gas marks.
- Grams to Cups ConverterA cup measures volume, but grams measure weight — so the conversion depends on the ingredient.
- Recipe ScalerPaste an ingredient list, set the original and new number of servings, and every quantity is scaled for you — with results shown as kitchen fractions like 1 ½ or ¾.
- Meat Temperature Chart & CalculatorLook up the safe minimum internal temperature for any meat, in Fahrenheit and Celsius.
- Candy Temperature ConverterFind the temperature for each sugar stage in both Fahrenheit and Celsius, adjusted for your altitude.
- Boiling Point at Altitude CalculatorWater boils at a lower temperature the higher you go, because air pressure falls.
- Fridge & Freezer Temperature GuideEnter your appliance thermometer reading to check whether your fridge or freezer is at a safe temperature, in °F or °C.
- Butter Converter (Sticks, Cups, Grams)Convert butter between US sticks, cups, tablespoons, grams and ounces — essential when using American recipes with a kitchen scale, or metric recipes with sticks.
- Oven to Air Fryer ConverterTurn any oven recipe into air fryer settings.
- Air Fryer to Oven ConverterCooking an air fryer recipe in your oven? Enter the air fryer temperature and time to get the equivalent conventional and convection oven settings.
- Slow Cooker to Oven ConverterConvert cooking times between a slow cooker and the oven in either direction, using the standard conversion ranges for Low and High settings.
- Turkey Cooking Time CalculatorPlan your Thanksgiving or holiday turkey.
- Grams to Teaspoons ConverterConvert small amounts between grams and teaspoons for a specific ingredient — sugar, salt, flour, butter, cocoa, honey and more.
- ML to Grams ConverterConvert a volume in milliliters into weight in grams for a chosen ingredient.
- Grams to ML ConverterConvert a weight in grams into a volume in milliliters — and cups and tablespoons — for a chosen ingredient.
- Baking Temperature ChartTypical oven temperatures for everything you bake — cakes, cookies, breads, pies, pastry and pizza — in °F, °C and gas mark, plus internal temperatures that tell you when it is done.
- Sous Vide Temperature ChartCommon sous vide temperatures and times for steak, chicken, pork, fish, eggs and vegetables.
- Bath Water Temperature ChartHow warm should bath water be? Safe temperatures for baby baths, adult baths, hot tubs and your water heater — plus how quickly hot water can scald.
- Steak Doneness Temperature ChartInternal temperatures for every steak doneness — from blue to well done — with the temperature to pull it off the heat so it finishes perfectly while resting.
- BBQ & Smoking Temperature ChartLow-and-slow smoker temperatures and the internal temperatures to aim for with brisket, pork shoulder, ribs, poultry and fish.
- Deep Frying Oil Temperature ChartThe right oil temperature for frying everything from French fries to donuts, and the smoke points that tell you which oils can take the heat.
- Chocolate Tempering TemperaturesTempering gives chocolate its shine and snap.
- Coffee & Tea Brewing Temperature ChartThe best water temperature for coffee and each type of tea, plus steeping times.
- Wine & Beer Serving Temperature ChartServing temperature changes how wine and beer taste.
- Bread Proofing Temperature ChartYeast works best in a narrow temperature range.
- Canning Temperature GuideSafe home canning depends on reaching the right temperature for the type of food.
- Cake Pan Size ConverterBaking in a different pan than the recipe calls for? Compare pan areas to see how much to scale the recipe and how baking time changes.
- Yeast ConverterSwap one type of yeast for another.
- Tablespoons to Grams ConverterConvert tablespoons to grams — or grams to tablespoons — for the ingredient you are using.
- Cups to Pounds ConverterHow many cups are in a 5 lb bag of flour? Convert between cups and pounds for common baking ingredients.
- Butter to Oil ConverterSwap butter for oil (or oil for butter) in a recipe with the correct ratio, and learn when the swap works.
- Fresh to Dried Herbs ConverterReplace fresh herbs with dried, or dried with fresh, using the standard 3-to-1 ratio.
- Egg Size ConverterRecipes assume large eggs.
- Sugar to Honey ConverterReplace granulated sugar with honey (or honey with sugar) and get the adjustments that keep your bake working.
- Pizza Oven Temperature ChartThe right temperature for every pizza style — from 90-second Neapolitan pies to home-oven pizza on a stone or steel.
- Grill Temperature ChartWhat do “low”, “medium” and “high” mean on a grill? Temperature ranges, the hand test and the right heat for each food.
Length & height converters
Centimeters, inches, feet, meters, miles and a height converter.
- CM to InchesConvert centimeters to inches.
- Inches to CMConvert inches to centimeters.
- CM to FeetConvert centimeters to feet.
- Feet to MetersConvert feet to meters.
- Meters to FeetConvert meters to feet.
- MM to InchesConvert millimeters to inches.
- MM to CMConvert millimeters to centimeters.
- KM to MilesConvert kilometers to miles.
- Miles to KMConvert miles to kilometers.
- Yards to FeetConvert yards to feet.
- Yards to MetersConvert yards to meters.
- CM to MMConvert centimeters to millimeters.
- Inches to FeetConvert inches to feet.
- Feet to InchesConvert feet to inches.
- Inches to MetersConvert inches to meters.
- Inches to MMConvert inches to millimeters.
- Feet to CMConvert feet to centimeters.
- CM to MetersConvert centimeters to meters.
- Meters to CMConvert meters to centimeters.
- Meters to YardsConvert meters to yards.
- Miles to FeetConvert miles to feet.
- MM to FeetConvert millimeters to feet.
- Nautical Miles to MilesConvert nautical miles to miles.
- Microns to MMConvert micrometers to millimeters.
- Hands to FeetConvert hands to feet.
- Light Years to KMConvert light-years to kilometers.
- Light Years to MilesConvert light-years to miles.
- MM to MetersConvert millimeters to meters.
- KM to MetersConvert kilometers to meters.
- Feet to MilesConvert feet to miles.
- Inches to YardsConvert inches to yards.
- Mils to MMConvert mils (thou) to millimeters.
- Height ConverterConvert your height between centimeters and feet-and-inches in either direction.
- Online Ruler (Actual Size)Measure small objects right on your screen.
- MM Ruler (Actual Size)A millimeter ruler for measuring small things on screen — jewelry, screws, rings and printouts.
- MM to Inches ChartA complete millimetres to inches conversion chart.
- MM to Inches Fraction CalculatorTurn a metric measurement into the nearest fraction of an inch you can find on a tape measure or drill set, and see how far off the fraction is.
- How to Convert MM to InchesTo convert millimetres to inches, divide by 25.4.
- CM to Inches ChartA printable centimetres to inches conversion chart.
- CM to Inches Fraction CalculatorTurn a centimetre measurement into the nearest fraction of an inch you can find on a tape measure, and see how close the fraction is.
- How to Convert CM to InchesTo convert centimetres to inches, divide by 2.54.
Weight converters
Kilograms, pounds, ounces, grams and stone.
- KG to LBSConvert kilograms to pounds.
- LBS to KGConvert pounds to kilograms.
- Grams to OuncesConvert grams to ounces.
- Ounces to GramsConvert ounces to grams.
- Stone to PoundsConvert stone to pounds.
- Stone to KGConvert stone to kilograms.
- Pounds to OuncesConvert pounds to ounces.
- Ounces to PoundsConvert ounces to pounds.
- Grams to PoundsConvert grams to pounds.
- MG to GramsConvert milligrams to grams.
- MCG to MGConvert micrograms to milligrams.
- Tons to PoundsConvert US tons to pounds.
- Carats to GramsConvert carats to grams.
- Grams to KGConvert grams to kilograms.
- KG to GramsConvert kilograms to grams.
- Pounds to GramsConvert pounds to grams.
- KG to StoneConvert kilograms to stone.
- LBS to StoneConvert pounds to stone.
- Troy Ounces to GramsConvert troy ounces to grams.
- Troy Ounces to OuncesConvert troy ounces to ounces.
- Tola to GramsConvert tolas to grams.
- Grains to GramsConvert grains to grams.
- KG to OzConvert kilograms to ounces.
- Oz to KGConvert ounces to kilograms.
- Short Tons to Metric TonsConvert US tons to metric tons.
- Gold Karat Purity CalculatorFind out how much pure gold is in 24K, 22K, 18K, 14K or 10K gold — as a percentage, a hallmark stamp and grams of pure gold.
Volume & liquid converters
Milliliters, fluid ounces, cups, spoons, liters and gallons.
- ML to OzConvert milliliters to US fluid ounces.
- Oz to MLConvert US fluid ounces to milliliters.
- Cups to MLConvert US cups to milliliters.
- Tablespoons to TeaspoonsConvert tablespoons to teaspoons.
- Teaspoons to MLConvert teaspoons to milliliters.
- Liters to GallonsConvert liters to US gallons.
- Gallons to LitersConvert US gallons to liters.
- Quarts to CupsConvert US quarts to US cups.
- Pints to CupsConvert US pints to US cups.
- Fluid Ounces to CupsConvert US fluid ounces to US cups.
- Liters to OuncesConvert liters to US fluid ounces.
- ML to LitersConvert milliliters to liters.
- CC to MLConvert cubic centimeters to milliliters.
- Cubic Inches to CCConvert cubic inches to cubic centimeters.
- Cups to TablespoonsConvert US cups to tablespoons.
- Tablespoons to CupsConvert tablespoons to US cups.
- Cups to OuncesConvert US cups to US fluid ounces.
- Ounces to TablespoonsConvert US fluid ounces to tablespoons.
- ML to CupsConvert milliliters to US cups.
- ML to TeaspoonsConvert milliliters to teaspoons.
- Liters to MLConvert liters to milliliters.
- Drops to MLConvert drops to milliliters.
- Gallons to OuncesConvert US gallons to US fluid ounces.
- Quarts to GallonsConvert US quarts to US gallons.
- Gallons to Cubic FeetConvert US gallons to cubic feet.
- Barrels to GallonsConvert oil barrels to US gallons.
- US Gallons to UK GallonsConvert US gallons to UK gallons.
- UK Gallons to US GallonsConvert UK gallons to US gallons.
- Tablespoons to MLConvert tablespoons to milliliters.
- ML to TablespoonsConvert milliliters to tablespoons.
- Cups to LitersConvert US cups to liters.
- Liters to CupsConvert liters to US cups.
- Gallons to CupsConvert US gallons to US cups.
- Cups to QuartsConvert US cups to US quarts.
- Cups to PintsConvert US cups to US pints.
- Gallons to MLConvert US gallons to milliliters.
- Liters to QuartsConvert liters to US quarts.
- Quarts to LitersConvert US quarts to liters.
- Pints to MLConvert US pints to milliliters.
- Cubic Meters to LitersConvert cubic meters to liters.
- Cubic Feet to GallonsConvert cubic feet to US gallons.
- Cubic Yards to Cubic FeetConvert cubic yards to cubic feet.
Electrical calculators
Watts, amps and volts, kWh, Ohm’s law and wire gauge sizing.
- Watts to Amps CalculatorFind how many amps an appliance or circuit draws from its wattage and voltage.
- Amps to Watts CalculatorConvert current in amps to power in watts at any voltage — for example, to see how much load a 15 A or 20 A circuit can carry.
- Volts to Watts CalculatorVolts alone do not tell you watts — you also need the current or the resistance.
- kWh CalculatorWork out how many kilowatt-hours a device uses, or the average power behind a kWh figure, and what that energy costs.
- Ohm’s Law CalculatorEnter any two of voltage (V), current (I), resistance (R) and power (P), and the calculator works out the other two.
- Wire Gauge CalculatorEstimate the wire gauge (AWG) needed for a circuit.
- AWG to mm² ConverterConvert wire sizes between American Wire Gauge (AWG) and metric cross-sectional area in mm², with diameter and the nearest standard metric size.
- kVA to kW ConverterConvert apparent power (kVA) to real power (kW) or back, using the power factor of the load.
Data & digital converters
MB, GB and TB, internet speed (Mbps to MB/s), pixels and DPI, and aspect ratios.
- MB to GBConvert megabytes to gigabytes.
- GB to MBConvert gigabytes to megabytes.
- GB to TBConvert gigabytes to terabytes.
- TB to GBConvert terabytes to gigabytes.
- Mbps to MB/sConvert megabits per second to megabytes per second.
- KB to MBConvert kilobytes to megabytes.
- Bits to BytesConvert bits to bytes.
- PT to PXConvert points to pixels.
- Kbps to MbpsConvert kilobits per second to megabits per second.
- Pixels to Inches (DPI) CalculatorFind out how large an image will print at a given resolution, or how many pixels you need for a print of a certain size.
- Aspect Ratio CalculatorFind the aspect ratio of an image, video or screen, and calculate a new width or height that keeps the same proportions when resizing.
- PX to REM ConverterConvert CSS pixel values to rem (and em), or rem back to pixels, using your project’s root font size — 16px by default.
- Hex to RGB ConverterPaste a hex color code or RGB values to convert between hex, RGB, HSL and CMYK — with a preview of the color.
- CMYK to RGB ConverterConvert print colors in CMYK (cyan, magenta, yellow, black) to RGB and hex for screens, with a preview.
- Color Temperature Converter (Kelvin to RGB)See what color a light bulb’s Kelvin rating looks like — 2700K warm white, 4000K neutral, 5000K daylight — as RGB and hex values.
- Paper Size ConverterLook up any standard paper size in inches, millimeters, centimeters, points and pixels — for example, A4 in inches or US Letter in mm.
- Number to Words ConverterWrite any number out in words — perfect for filling in checks, legal documents and invoices.
- Case ConverterPaste any text and convert it to UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case or kebab-case in one click.
- Base64 Encoder / DecoderEncode any text as Base64 or decode Base64 back into readable text.
- Morse Code TranslatorType text to convert it to Morse code dots and dashes, or paste Morse code to decode it back to letters and numbers.
- Text to Binary ConverterTurn any text into binary — the ones and zeros computers store — or decode 8-bit binary back into text.
- ASCII ConverterLook up the ASCII (and Unicode) code of every character in your text, or turn a list of codes back into text.
- EM to PX & VH to PX ConverterConvert relative CSS units into pixels.
- HSL to Hex ConverterEnter a hue, saturation and lightness to get the hex and RGB color codes, with a preview swatch.
- RGB to CMYK ConverterConvert screen colors (RGB) to CMYK ink percentages for print design.
- TV Size CalculatorFind out how wide and tall a TV screen is from its diagonal size, and how far to sit from it.
- Screen Resolution ConverterCompare screen resolutions and calculate total pixels, aspect ratio and pixel density (PPI) for any screen size.
- Megapixels to Print Size CalculatorHow big can you print a 12, 24 or 48 megapixel photo? Find the pixel dimensions and print sizes at different quality levels.
- Photo Size Converter (Inches to Pixels)Find how many pixels you need for a standard photo print size, such as 4x6 or 8x10, at your chosen resolution.
Speed, area & engineering converters
mph, km/h, knots, square feet, acres, horsepower, psi, torque and energy.
- MPH to KM/HConvert miles per hour to kilometers per hour.
- KM/H to MPHConvert kilometers per hour to miles per hour.
- Knots to MPHConvert knots to miles per hour.
- Square Feet to Square MetersConvert square feet to square meters.
- Square Meters to Square FeetConvert square meters to square feet.
- Acres to Square FeetConvert acres to square feet.
- Hectares to AcresConvert hectares to acres.
- kW to HPConvert kilowatts to horsepower.
- PSI to BarConvert pounds per square inch to bar.
- Newton Meters to Foot PoundsConvert newton meters to foot-pounds.
- Joules to CaloriesConvert joules to calories.
- kJ to CaloriesConvert kilojoules to kilocalories (food Calories).
- Calories to kJConvert kilocalories (food Calories) to kilojoules.
- Calories to JoulesConvert calories to joules.
- Square Inches to Square CMConvert square inches to square centimeters.
- Square Yards to Square FeetConvert square yards to square feet.
- Square KM to Square MilesConvert square kilometers to square miles.
- Acres to HectaresConvert acres to hectares.
- Newtons to KGConvert newtons to kilograms-force.
- Newtons to PoundsConvert newtons to pounds-force.
- M/S to KM/HConvert meters per second to kilometers per hour.
- Feet per Second to MPHConvert feet per second to miles per hour.
- km/L to MPGConvert kilometers per liter to miles per US gallon.
- GPM to LPMConvert US gallons per minute to liters per minute.
- CFM to m³/hConvert cubic feet per minute to cubic meters per hour.
- Lux to Foot-CandlesConvert lux to foot-candles.
- Square Feet to AcresConvert square feet to acres.
- Square Meters to AcresConvert square meters to acres.
- Square Feet to Square YardsConvert square feet to square yards.
- Square Meters to HectaresConvert square meters to hectares.
- Bar to PSIConvert bar to pounds per square inch.
- kPa to PSIConvert kilopascals to pounds per square inch.
- PSI to kPaConvert pounds per square inch to kilopascals.
- MPa to PSIConvert megapascals to pounds per square inch.
- Horsepower to WattsConvert horsepower to watts.
- Watts to HorsepowerConvert watts to horsepower.
- kWh to JoulesConvert kilowatt-hours to joules.
- Inch-Pounds to Foot-PoundsConvert inch-pounds to foot-pounds.
- Hz to kHzConvert hertz to kilohertz.
- Hz to MHzConvert hertz to megahertz.
- kHz to MHzConvert kilohertz to megahertz.
- RPM to rad/sConvert revolutions per minute to radians per second.
- Cubic Feet CalculatorCalculate the volume of a box, room, container or space in cubic feet, and see it in cubic yards, cubic meters, liters and US gallons.
- Pressure Converter (atm, mmHg, kPa)Convert a pressure between all the common units at once — atmospheres, millimeters of mercury, kilopascals, psi, bar, inches of mercury and pascals.
- Lumens to Watts CalculatorFind how many watts a bulb needs for a given brightness in lumens — or the lumens you get from a wattage — for LED, CFL, halogen and incandescent bulbs.
- Decibel ConverterConvert between decibels and ratios.
- Mach ConverterConvert between Mach number and everyday speed units.
- MPG to L/100km ConverterConvert fuel economy between miles per gallon (US or UK), liters per 100 kilometers and kilometers per liter.
- Watts to Lumens ConverterHow bright is a 60-watt bulb, and which LED matches it? Convert watts to lumens for each bulb type.
- L/100km to MPG ConverterConvert a fuel consumption figure in L/100 km — as used in Europe, Canada and Australia — into US or UK miles per gallon.
- Frequency to Wavelength CalculatorCalculate the wavelength of a radio signal, light or sound from its frequency — or the frequency from a wavelength.
Home energy & HVAC calculators
BTU, AC size, HVAC tonnage, electricity and heating costs, water and pool heaters.
- BTU to kWConvert BTU per hour to kilowatts.
- BTU to TonsConvert BTU per hour to tons of refrigeration.
- Watts to BTUConvert watts to BTU per hour.
- Therms to kWhConvert US therms to kilowatt-hours.
- BTU CalculatorFind the right air conditioner size for a room.
- AC Size CalculatorEstimate the central air conditioner size for a whole home.
- HVAC Tonnage CalculatorWork out HVAC tonnage either from floor area (using square feet per ton for your climate) or by converting a known cooling load from BTU per hour to tons.
- Thermostat Energy Savings CalculatorSetting your thermostat back while you sleep or are away is one of the simplest ways to cut energy bills.
- Electricity Cost CalculatorFind out how much any appliance or device costs to run.
- Space Heater Cost CalculatorSee exactly what your electric space heater costs to run.
- Water Heater Size CalculatorSize a water heater by your busiest hour of hot water use.
- Pool Heater CalculatorEstimate how many BTUs it takes to warm your pool and how long your heater will need.
- Thermostat Setting GuideRecommended thermostat settings for comfort and lower energy bills, in winter and summer, while you are home, asleep or away.
- Ideal Room Temperature GuideWhat temperature should each room be? Recommended ranges for sleeping, babies, living areas, offices and older adults.
- Aquarium Temperature ChartKeep your fish healthy at the right water temperature.
- Reptile Tank Temperature ChartReptiles need a temperature gradient to regulate their body heat.
- Pet Temperature ChartPets run warmer than people.
- Washing Machine Temperature ChartLaundry labels give wash temperatures in °C.
- Ironing Temperature ChartSet your iron to the right temperature for each fabric to remove wrinkles without scorching or melting.
- Candle Wax Melting Temperature ChartMelting points and typical heating and pouring temperatures for common candle waxes.
- Compost Temperature GuideA healthy hot compost pile heats itself.
Home improvement calculators
Concrete, mulch and gravel, square footage and paint.
- Concrete CalculatorWork out how much concrete to order for a slab, patio, shed base or driveway.
- Mulch & Gravel CalculatorEstimate how much mulch, gravel, topsoil or sand to buy for a garden bed, path or driveway, in cubic yards, approximate tons and bags.
- Square Footage CalculatorCalculate the area of a room, floor, lot or any simple shape in square feet, and optionally the total cost from a price per square foot.
- Paint CalculatorWork out how much paint to buy for a room.
- Sheet Metal Gauge to MM ConverterFind the thickness of a sheet metal gauge in mm and inches.
- Feet and Inches CalculatorDo math with feet and inches the way carpenters need it — add or subtract two lengths, or multiply and divide by a number.
- Inches to Decimal & Decimal Feet ConverterConvert between decimal feet used on plans and surveys and the feet-and-inches used on tape measures.
- Lumber Size Converter (Nominal to Actual)A 2x4 isn’t 2 by 4 inches.
- Board Feet CalculatorCalculate how many board feet of lumber you are buying — and what it costs — for hardwood and rough lumber priced by the board foot.
- Pipe Size Converter (NPS to MM)Find the real outside diameter of a nominal pipe size and its metric DN equivalent — for steel and PVC pipe.
- Wrench & Socket Size ConverterFind the closest metric or SAE wrench or socket size, and whether it is a safe substitute.
- Drill Bit Size ConverterConvert a drill bit size between fractional inches, letter sizes and metric — and find the nearest bit in each system.
- Sandpaper Grit ConverterCompare sandpaper grits between the US (CAMI) and European (FEPA “P”) systems, and see what each grit is for.
- Mesh to Micron ConverterConvert screen and sieve mesh numbers to opening size in microns (µm) and millimeters, or find the mesh for a particle size.
- Thread Pitch ConverterConvert between inch threads (threads per inch) and metric thread pitch (mm between threads).
- Paint Application Temperature GuidePaint needs the right temperature to cure properly.
- Concrete Curing Temperature GuideConcrete gains strength through a chemical reaction that depends on temperature.
Tech & auto temperature guides
Safe CPU and GPU temperatures, engine and tire temperatures, and sensor (PT100, thermocouple) conversions.
- Tire Pressure vs Temperature CalculatorTire pressure drops when it gets cold and rises when it warms up.
- Thermocouple & PT100 ConverterFor engineers and technicians: convert between temperature and PT100/PT1000 resistance or type K thermocouple voltage.
- Normal CPU & GPU Temperature GuideIs your computer running too hot? Typical CPU and GPU temperatures at idle and under load, and the limits where performance throttles.
- Car Engine Temperature GuideWhat temperature should your engine run at? Normal coolant, oil and transmission temperatures, and when the needle means trouble.
- 3D Printer Filament Temperature ChartStarting nozzle and print-bed temperatures for common 3D printing filaments.
- Soldering Iron Temperature ChartWhat temperature should your soldering iron be? Tip temperatures for leaded and lead-free solder and common jobs.
- Kiln Cone Temperature ChartPyrometric cone temperatures for firing pottery and ceramics, from low-fire glazes to high-fire stoneware and porcelain.
- Metal Melting Point ChartMelting temperatures of common metals and alloys for casting, metalworking and reference.
- Boiling Point of Liquids ChartBoiling points of common liquids at standard atmospheric pressure (1 atm), from liquid nitrogen to glycerol.
Size converters
Shoe, ring and clothing sizes for US, UK and EU.
- Shoe Size ConverterConvert shoe sizes between US, UK and European systems for men and women, and see the matching foot length.
- Ring Size ConverterConvert a ring size between US numbers, UK letters, European (ISO) circumference and inside diameter.
- Clothing Size ConverterConvert clothing sizes between the US, UK and Europe for women's dresses and tops, men's suits and jackets, and men's dress shirts.
- Tire Size ConverterDecode a metric tire size into inches and compare it with another size to see the diameter difference and speedometer effect.
- Bra Size ConverterConvert a US bra size to UK, European, French/Spanish and Australian sizes.
- Hat Size ConverterMeasure your head and convert it to fitted hat sizes in the US, UK and Europe, plus letter sizes.
- Glove Size ConverterMeasure around your hand and convert it to glove sizes — numeric (6–11), EU and letter sizes S to XXL.
- Kids Shoe Size ConverterConvert children’s shoe sizes between US toddler (C) and youth (Y) sizes, UK and EU — or find a size from foot length.
- Knitting Needle Size ConverterConvert knitting needle sizes between the US system, metric millimeters and the old UK/Canadian numbering.
- Crochet Hook Size ConverterConvert crochet hook sizes between metric millimeters and US letter-number sizes such as H-8 and J-10.
Everyday calculators
Time zone converter and fuel cost calculator.