8 mm to Inches
8 mm ≈ 0.315 in
8 millimeters is approximately 0.315 inches.
How to convert 8 mm to in
Use the formula in = mm ÷ 25.4:
in = 8 ÷ 25.4in = 0.314961
So 8 mm = 0.314961 in, or about 0.315 in rounded.
Rounded values and quick estimate
- Rounded to a whole number: 0 in
- Rounded to one decimal place: 0.3 in
- Conversion factor: 1 millimeter = 0.0394 inches
Quick mental estimate: divide by 25. For 8 mm that gives about 0.32 in — off by 0.005039 in (1.6%). Use the exact formula when precision matters.
8 mm in other units
8 mm is 0.315 inches, almost exactly 5/16″ (0.3125″ = 7.94 mm). It is the diameter of M8 bolts and a common drill, dowel and rope size.
- Inches
- 0.315 in
- Centimeters
- 0.8 cm
- Meters
- 0.008 m
- Kilometers
- 0.000008 km
- Feet
- 0.0262 ft
- Yards
- 0.008749 yd
- Miles
- 0.000005 mi
- Micrometers
- 8000 µm
- Hands
- 0.0787 hh
- Nautical miles
- 0.000004 nmi
- Nanometers
- 8000000 nm
- Angstroms
- 80000000 Å
- Decimeters
- 0.08 dm
- Points (typographic)
- 22.68 pt
- Picas
- 1.89 P
- Fathoms
- 0.004374 ftm
- Rods
- 0.001591 rd
- Chains
- 0.000398 ch
- Furlongs
- 0.00004 fur
- Leagues
- 0.000002 lea
- Mils (thou)
- 314.96 mil
8 mm and nearby values
About millimeters and inches
A millimeter is one thousandth of a meter (0.1 cm). It is used for small, precise measurements like rainfall, screws and paper thickness.
An inch is defined as exactly 2.54 centimeters. There are 12 inches in a foot; inches are used in the US for screens, heights and small lengths.
Related conversions
Frequently asked questions
What is 8 mm in Inches?
8 millimeters is about 0.315 inches (8 mm ≈ 0.315 in).
How do you convert 8 mm to in?
Apply in = mm ÷ 25.4: in = 8 ÷ 25.4, in = 0.314961.
How many millimeters is 0.315 in?
0.315 in is about 8 millimeters.
Is 8 mm the same as 5/16 inch?
Very nearly — they differ by only 0.06 mm — but M8 and 5/16″ bolts have different thread pitches, so their nuts are not interchangeable.