Metric to Imperial Conversion
This page is the reference chart for converting metric measurements (millimeters, centimeters, meters) to imperial inches, feet, and yards, and back. Every factor below uses the official 1959 inch definition: 1 inch equals exactly 25.4 mm, with no rounding.
For an interactive version that does the arithmetic for you and lets you pick mm, cm, or m as the input unit, use the Metric to Imperial Converter.
Conversion Factors
- 1 inch = 25.4 mm (exact, by international definition)
- 1 mm = 0.0393700787 inches
- 1 cm = 0.3937007874 inches
- 1 meter = 39.3700787 inches = 3.2808 feet
- 1 foot = 304.8 mm = 30.48 cm
- 1 yard = 0.9144 meters
Inch to MM Reference Chart
| Fraction | Decimal (in) | Millimeters |
|---|---|---|
| 1/64" | 0.015625 | 0.3969 |
| 1/32" | 0.03125 | 0.7937 |
| 3/64" | 0.046875 | 1.1906 |
| 1/16" | 0.0625 | 1.5875 |
| 5/64" | 0.078125 | 1.9844 |
| 3/32" | 0.09375 | 2.3812 |
| 7/64" | 0.109375 | 2.7781 |
| 1/8" | 0.125 | 3.175 |
| 9/64" | 0.140625 | 3.5719 |
| 5/32" | 0.15625 | 3.9688 |
| 11/64" | 0.171875 | 4.3656 |
| 3/16" | 0.1875 | 4.7625 |
| 13/64" | 0.203125 | 5.1594 |
| 7/32" | 0.21875 | 5.5562 |
| 15/64" | 0.234375 | 5.9531 |
| 1/4" | 0.25 | 6.35 |
| 17/64" | 0.265625 | 6.7469 |
| 9/32" | 0.28125 | 7.1437 |
| 19/64" | 0.296875 | 7.5406 |
| 5/16" | 0.3125 | 7.9375 |
| 21/64" | 0.328125 | 8.3344 |
| 11/32" | 0.34375 | 8.7312 |
| 23/64" | 0.359375 | 9.1281 |
| 3/8" | 0.375 | 9.525 |
| 25/64" | 0.390625 | 9.9219 |
| 13/32" | 0.40625 | 10.3187 |
| 27/64" | 0.421875 | 10.7156 |
| 7/16" | 0.4375 | 11.1125 |
| 29/64" | 0.453125 | 11.5094 |
| 15/32" | 0.46875 | 11.9063 |
| 31/64" | 0.484375 | 12.3031 |
| 1/2" | 0.5 | 12.7 |
| 33/64" | 0.515625 | 13.0969 |
| 17/32" | 0.53125 | 13.4937 |
| 35/64" | 0.546875 | 13.8906 |
| 9/16" | 0.5625 | 14.2875 |
| 37/64" | 0.578125 | 14.6844 |
| 19/32" | 0.59375 | 15.0812 |
| 39/64" | 0.609375 | 15.4781 |
| 5/8" | 0.625 | 15.875 |
| 41/64" | 0.640625 | 16.2719 |
| 21/32" | 0.65625 | 16.6687 |
| 43/64" | 0.671875 | 17.0656 |
| 11/16" | 0.6875 | 17.4625 |
| 45/64" | 0.703125 | 17.8594 |
| 23/32" | 0.71875 | 18.2562 |
| 47/64" | 0.734375 | 18.6531 |
| 3/4" | 0.75 | 19.05 |
| 49/64" | 0.765625 | 19.4469 |
| 25/32" | 0.78125 | 19.8438 |
| 51/64" | 0.796875 | 20.2406 |
| 13/16" | 0.8125 | 20.6375 |
| 53/64" | 0.828125 | 21.0344 |
| 27/32" | 0.84375 | 21.4312 |
| 55/64" | 0.859375 | 21.8281 |
| 7/8" | 0.875 | 22.225 |
| 57/64" | 0.890625 | 22.6219 |
| 29/32" | 0.90625 | 23.0187 |
| 59/64" | 0.921875 | 23.4156 |
| 15/16" | 0.9375 | 23.8125 |
| 61/64" | 0.953125 | 24.2094 |
| 31/32" | 0.96875 | 24.6062 |
| 63/64" | 0.984375 | 25.0031 |
| 1" | 1 | 25.4 |
Metric and Imperial in the Same Project
Mixing metric and imperial parts on one build is common when a metric fastener, a metric plywood sheet, or an imported part needs to fit inch-based stock or hardware. Convert every measurement into one system before cutting or drilling, rather than rounding each part to the "closest" value in the other system and hoping the fit works out. See the Inches to MM Calculator or the MM to Inches Calculator to convert individual measurements as you go.
Frequently Asked Questions
Related Tools
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