-1 Fahrenheit to Celsius
-1 °F ≈ -18.33 °C
-1 degree Fahrenheit is approximately -18.33 degrees Celsius.
How to convert -1 °F to °C
Use the formula °C = (°F − 32) × 5/9:
°C = (-1 − 32) × 5/9°C = -33 × 5/9°C = -18.333333
So -1 °F = -18.333333 °C, or about -18.33 °C rounded.
Rounded values and quick estimate
- Rounded to a whole number: -18 °C
- Rounded to one decimal place: -18.3 °C
Quick mental estimate: subtract 30 and halve it. For -1 °F that gives about -15.5 °C — off by 2.83 °C (15.5%). Use the exact formula when precision matters.
-1 Fahrenheit in other units
-18.33 °C is very cold weather, well below the freezing point of water. It is typical of a hard winter in northern climates; warm layers, gloves and a hat are essential outdoors.
- Celsius
- -18.33 °C
- Degrees Réaumur
- -14.67 °Ré
- Degrees Delisle
- 177.5 °De
- Degrees Newton
- -6.05 °N
- Degrees Rømer
- -2.13 °Rø
- Kelvin
- 254.82 K
- Rankine
- 458.67 °R
-1 °F and nearby values
About fahrenheit and celsius
The Fahrenheit scale puts water’s freezing point at 32 °F and boiling point at 212 °F. It is the everyday temperature scale in the United States.
The Celsius scale sets the freezing point of water at 0 °C and its boiling point at 100 °C (at sea level). It is used for everyday temperatures in almost every country.
Related conversions
Frequently asked questions
What is -1 Fahrenheit in Celsius?
-1 degree Fahrenheit is about -18.33 degrees Celsius (-1 °F ≈ -18.33 °C).
How do you convert -1 °F to °C?
Apply °C = (°F − 32) × 5/9: °C = (-1 − 32) × 5/9, °C = -33 × 5/9, °C = -18.333333.
How many degrees Fahrenheit is -18.33 °C?
-18.33 °C is about -0.994 degrees Fahrenheit.