Fraction, Decimal & Millimeter Conversion Chart
When working on go-karts, minibikes, trailers, engines, and other mechanical projects, you may encounter measurements listed as fractions, decimals, or millimeters. Knowing how these measurements relate to one another can make it easier to select the correct bolt, axle, bearing, wheel, tire, or other component.
This conversion chart provides common inch fractions, decimal inch measurements, and their metric millimeter equivalents.
Inches to Decimal and Millimeter Conversion Chart
| Fraction | Decimal Inches | Millimeters |
|---|---|---|
| 1/32" | 0.03125" | 0.79 mm |
| 1/16" | 0.0625" | 1.59 mm |
| 3/32" | 0.09375" | 2.38 mm |
| 1/8" | 0.125" | 3.18 mm |
| 5/32" | 0.15625" | 3.97 mm |
| 3/16" | 0.1875" | 4.76 mm |
| 7/32" | 0.21875" | 5.56 mm |
| 1/4" | 0.250" | 6.35 mm |
| 9/32" | 0.28125" | 7.14 mm |
| 5/16" | 0.3125" | 7.94 mm |
| 11/32" | 0.34375" | 8.73 mm |
| 3/8" | 0.375" | 9.53 mm |
| 13/32" | 0.40625" | 10.32 mm |
| 7/16" | 0.4375" | 11.11 mm |
| 15/32" | 0.46875" | 11.91 mm |
| 1/2" | 0.500" | 12.70 mm |
| 17/32" | 0.53125" | 13.49 mm |
| 9/16" | 0.5625" | 14.29 mm |
| 19/32" | 0.59375" | 15.08 mm |
| 5/8" | 0.625" | 15.88 mm |
| 21/32" | 0.65625" | 16.67 mm |
| 11/16" | 0.6875" | 17.46 mm |
| 23/32" | 0.71875" | 18.26 mm |
| 3/4" | 0.750" | 19.05 mm |
| 25/32" | 0.78125" | 19.84 mm |
| 13/16" | 0.8125" | 20.64 mm |
| 27/32" | 0.84375" | 21.43 mm |
| 7/8" | 0.875" | 22.23 mm |
| 29/32" | 0.90625" | 23.02 mm |
| 15/16" | 0.9375" | 23.81 mm |
| 31/32" | 0.96875" | 24.61 mm |
| 1" | 1.000" | 25.40 mm |
Common Fraction-to-Millimeter Conversions
- 1/4" = 6.35 mm
- 5/16" = 7.94 mm
- 3/8" = 9.53 mm
- 7/16" = 11.11 mm
- 1/2" = 12.70 mm
- 9/16" = 14.29 mm
- 5/8" = 15.88 mm
- 11/16" = 17.46 mm
- 3/4" = 19.05 mm
- 13/16" = 20.64 mm
- 7/8" = 22.23 mm
- 15/16" = 23.81 mm
- 1" = 25.40 mm
How to Convert Inches to Millimeters
To convert an inch measurement to millimeters, multiply the measurement by 25.4.
For example:
3/4" × 25.4 = 19.05 mm
Therefore, 3/4 inch is equal to 19.05 mm.
How to Convert Millimeters to Inches
To convert millimeters to inches, divide the measurement by 25.4.
For example:
19.05 mm ÷ 25.4 = 0.750"
Therefore, 19.05 mm is equal to 3/4 inch.
