Inches to millimetre conversion table:
(With decimal equivalents)
The metals industry can be rather confusing when sourcing items from international suppliers. American suppliers still use gauges and inches when referring to metal thicknesses. For more information on gauges see our article on the differences between sheet, plate and coil. For simple conversions use the table below.
| Inch | Inch/Decimal | mm | Inch | Inch/Decimal | mm | |
|---|---|---|---|---|---|---|
| 1/64″ | .01562 | 0.397 | 33/64″ | .51562 | 13.097 | |
| 1/32″ | .0312 | 0.794 | 17/32″ | .53125 | 13.494 | |
| 3/64″ | .04687 | 1.191 | 35/64″ | .54687 | 13.891 | |
| 1/16″ | .0625 | 1.588 | 9/16″ | .5625 | 14.287 | |
| 5/64″ | .07812 | 1.984 | 37/64″ | .57812 | 14.684 | |
| 3/32″ | .0937 | 2.381 | 19/32″ | .59375 | 15.081 | |
| 7/64″ | .10937 | 2.778 | 39/64″ | .60937 | 15.478 | |
| 1/8″ | .125 | 3.175 | 5/8″ | .625 | 15.875 | |
| 9/64″ | .14062 | 3.572 | 41/64″ | .64062 | 16.272 | |
| 5/32″ | .1562 | 3.969 | 21/32″ | .65625 | 16.669 | |
| 11/64″ | .17187 | 4.366 | 43/64″ | .67187 | 17.066 | |
| 3/16″ | .1875 | 4.763 | 11/16″ | .6875 | 17.462 | |
| 13/64″ | .20312 | 5.159 | 45/64″ | .70312 | 17.859 | |
| 7/32″ | .21875 | 5.556 | 23/32″ | .71875 | 18.256 | |
| 15/64″ | .23437 | 5.953 | 47/64″ | .73437 | 18.653 | |
| 1/4″ | .25 | 6.350 | 3/4″ | .75 | 19.050 | |
| 17/64″ | .26562 | 6.747 | 49/64″ | .76562 | 19.447 | |
| 9/32″ | .28125 | 7.144 | 25/32″ | .78125 | 19.844 | |
| 19/64″ | .29687 | 7.541 | 51/64″ | .79687 | 20.241 | |
| 5/16″ | .3125 | 7.937 | 13/16″ | .8125 | 20.637 | |
| 21/64″ | .32812 | 8.334 | 53/64″ | .82812 | 21.034 | |
| 11/32″ | .34375 | 8.731 | 27/32″ | .84375 | 21.431 | |
| 23/64″ | .35937 | 9.128 | 55/64″ | .85937 | 21.828 | |
| 3/8″ | .375 | 9.525 | 7/8″ | .875 | 22.225 | |
| 25/64″ | .39062 | 9.922 | 57/64″ | .89062 | 22.622 | |
| 13/32″ | .40625 | 10.319 | 29/32″ | .90625 | 23.019 | |
| 27/64″ | .42187 | 10.716 | 59/64″ | .92187 | 23.416 | |
| 7/16″ | .4375 | 11.112 | 15/16″ | .9375 | 23.812 | |
| 29/64″ | .45312 | 11.509 | 61/64″ | .95312 | 24.209 | |
| 15/32″ | .46875 | 11.906 | 31/32″ | .96875 | 24.606 | |
| 31/64″ | .48437 | 12.303 | 63/64″ | .98437 | 25.003 | |
| 1/2″ | .5 | 12.700 | 1″ | 1.0 | 25.400 |
