Fractional Inches to Millimetre Conversions

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