Converticious
Convert an inch fraction to millimeters (3/8″, 5/16″, 1 1/2″…) or find the nearest inch fraction for a measurement in mm. Handy for hardware, plumbing, woodworking and drawings in inches. 1 inch = 25.4 mm exactly.
Inches and fraction to mm and cm
Millimeters to inch fraction
Chart: common inch fractions (1/16) to mm
| Fraction | Decimal inches | Millimeters (mm) |
|---|---|---|
| 1/16″ | 0.0625 | 1.588 |
| 1/8″ | 0.125 | 3.175 |
| 3/16″ | 0.1875 | 4.762 |
| 1/4″ | 0.25 | 6.35 |
| 5/16″ | 0.3125 | 7.938 |
| 3/8″ | 0.375 | 9.525 |
| 7/16″ | 0.4375 | 11.112 |
| 1/2″ | 0.5 | 12.7 |
| 9/16″ | 0.5625 | 14.288 |
| 5/8″ | 0.625 | 15.875 |
| 11/16″ | 0.6875 | 17.463 |
| 3/4″ | 0.75 | 19.05 |
| 13/16″ | 0.8125 | 20.638 |
| 7/8″ | 0.875 | 22.225 |
| 15/16″ | 0.9375 | 23.813 |
| 1″ | 1 | 25.4 |
Chart: whole inches to mm and cm
| Inches | mm | cm |
|---|---|---|
| 1″ | 25.4 | 2.54 |
| 2″ | 50.8 | 5.08 |
| 3″ | 76.2 | 7.62 |
| 4″ | 101.6 | 10.16 |
| 5″ | 127 | 12.7 |
| 6″ | 152.4 | 15.24 |
| 7″ | 177.8 | 17.78 |
| 8″ | 203.2 | 20.32 |
| 9″ | 228.6 | 22.86 |
| 10″ | 254 | 25.4 |
| 11″ | 279.4 | 27.94 |
| 12″ | 304.8 | 30.48 |
| 18″ | 457.2 | 45.72 |
| 24″ | 609.6 | 60.96 |
| 36″ | 914.4 | 91.44 |
Full chart: inches to mm in 1/64 steps
| Fraction | Decimal inches | Millimeters (mm) |
|---|---|---|
| 1/64″ | 0.015625 | 0.397 |
| 1/32″ | 0.03125 | 0.794 |
| 3/64″ | 0.046875 | 1.191 |
| 1/16″ | 0.0625 | 1.588 |
| 5/64″ | 0.078125 | 1.984 |
| 3/32″ | 0.09375 | 2.381 |
| 7/64″ | 0.109375 | 2.778 |
| 1/8″ | 0.125 | 3.175 |
| 9/64″ | 0.140625 | 3.572 |
| 5/32″ | 0.15625 | 3.969 |
| 11/64″ | 0.171875 | 4.366 |
| 3/16″ | 0.1875 | 4.762 |
| 13/64″ | 0.203125 | 5.159 |
| 7/32″ | 0.21875 | 5.556 |
| 15/64″ | 0.234375 | 5.953 |
| 1/4″ | 0.25 | 6.35 |
| 17/64″ | 0.265625 | 6.747 |
| 9/32″ | 0.28125 | 7.144 |
| 19/64″ | 0.296875 | 7.541 |
| 5/16″ | 0.3125 | 7.938 |
| 21/64″ | 0.328125 | 8.334 |
| 11/32″ | 0.34375 | 8.731 |
| 23/64″ | 0.359375 | 9.128 |
| 3/8″ | 0.375 | 9.525 |
| 25/64″ | 0.390625 | 9.922 |
| 13/32″ | 0.40625 | 10.319 |
| 27/64″ | 0.421875 | 10.716 |
| 7/16″ | 0.4375 | 11.112 |
| 29/64″ | 0.453125 | 11.509 |
| 15/32″ | 0.46875 | 11.906 |
| 31/64″ | 0.484375 | 12.303 |
| 1/2″ | 0.5 | 12.7 |
| 33/64″ | 0.515625 | 13.097 |
| 17/32″ | 0.53125 | 13.494 |
| 35/64″ | 0.546875 | 13.891 |
| 9/16″ | 0.5625 | 14.288 |
| 37/64″ | 0.578125 | 14.684 |
| 19/32″ | 0.59375 | 15.081 |
| 39/64″ | 0.609375 | 15.478 |
| 5/8″ | 0.625 | 15.875 |
| 41/64″ | 0.640625 | 16.272 |
| 21/32″ | 0.65625 | 16.669 |
| 43/64″ | 0.671875 | 17.066 |
| 11/16″ | 0.6875 | 17.463 |
| 45/64″ | 0.703125 | 17.859 |
| 23/32″ | 0.71875 | 18.256 |
| 47/64″ | 0.734375 | 18.653 |
| 3/4″ | 0.75 | 19.05 |
| 49/64″ | 0.765625 | 19.447 |
| 25/32″ | 0.78125 | 19.844 |
| 51/64″ | 0.796875 | 20.241 |
| 13/16″ | 0.8125 | 20.638 |
| 53/64″ | 0.828125 | 21.034 |
| 27/32″ | 0.84375 | 21.431 |
| 55/64″ | 0.859375 | 21.828 |
| 7/8″ | 0.875 | 22.225 |
| 57/64″ | 0.890625 | 22.622 |
| 29/32″ | 0.90625 | 23.019 |
| 59/64″ | 0.921875 | 23.416 |
| 15/16″ | 0.9375 | 23.813 |
| 61/64″ | 0.953125 | 24.209 |
| 31/32″ | 0.96875 | 24.606 |
| 63/64″ | 0.984375 | 25.003 |
| 1″ | 1 | 25.4 |
Frequently asked questions
How many mm in an inch? Exactly 25.4 mm.
1/2 inch in mm? 12.7 mm. 1/4 inch in mm? 6.35 mm. 3/8 inch in mm? 9.525 mm. 3/4 inch in mm? 19.05 mm.
How do you convert an inch fraction to mm? Divide the numerator by the denominator, then multiply by 25.4. Example for 3/8: 3 ÷ 8 = 0.375; 0.375 × 25.4 = 9.525 mm.
How do you convert mm to an inch fraction? Divide by 25.4, then round to the nearest fraction. Example: 10 mm = 0.3937″, about 25/64″ (0.08 mm off).
Other converters
