Use this table to work out what the equivalent of imperial inch fractions is in decimal or metric millimetres.
If you would like a pdf file of the table which you can download and print it can be found here (opens in new window): Inch Fractions to Decimal and Millimetres Printable PDF.
Inch Fraction | Inch Decimal | Metric (mm) |
1/64 | .0156 | 0.397 |
1/32 | .0312 | 0.794 |
3/64 | .0469 | 1.191 |
1/16 | .0625 | 1.587 |
5/64 | .0781 | 1.984 |
3/32 | .0937 | 2.381 |
7/64 | .1094 | 2.778 |
1/8 | .1250 | 3.175 |
9/64 | .1406 | 3.572 |
5/32 | .1562 | 3.969 |
11/64 | .1719 | 4.366 |
3/16 | .1875 | 4.762 |
13/64 | .2031 | 5.159 |
7/32 | .2187 | 5.556 |
15/64 | .2344 | 5.953 |
1/4 | .2500 | 6.350 |
17/64 | .2656 | 6.747 |
9/32 | .2812 | 7.144 |
19/64 | .2969 | 7.540 |
5/16 | .3125 | 7.937 |
21/64 | .3281 | 8.334 |
11/32 | .3437 | 8.731 |
23/64 | .3594 | 9.128 |
3/8 | .3750 | 9.525 |
25/64 | .3906 | 9.922 |
13/32 | .4062 | 10.319 |
27/64 | .4219 | 10.716 |
7/16 | .4375 | 11.112 |
29/64 | .4531 | 11.509 |
15/32 | .4687 | 11.906 |
31/64 | .4844 | 12.303 |
1/2 | .5000 | 12.700 |
33/64 | .5156 | 13.097 |
17/32 | .5312 | 13.494 |
35/64 | .5469 | 13.891 |
9/16 | .5625 | 14.288 |
37/64 | .5781 | 14.686 |
19/32 | .5937 | 15.081 |
39/64 | .6094 | 15.478 |
5/8 | .6250 | 15.875 |
41/64 | .6406 | 16.272 |
21/32 | .6562 | 16.669 |
43/64 | .6719 | 17.065 |
11/16 | .6875 | 17.462 |
45/64 | .7031 | 17.859 |
23/32 | .7187 | 18.256 |
47/64 | .7344 | 18.653 |
3/4 | .7500 | 19.050 |
49/64 | .7656 | 19.447 |
25/32 | .7812 | 19.844 |
51/64 | .7969 | 20.241 |
13/16 | .8125 | 20.637 |
53/64 | .8281 | 21.034 |
27/32 | .8437 | 21.431 |
55/64 | .8594 | 21.828 |
7/8 | .8750 | 22.225 |
57/64 | .8906 | 22.622 |
29/32 | .9062 | 23.019 |
59/64 | .9219 | 23.416 |
15/16 | .9375 | 23.812 |
61/64 | .9531 | 24.209 |
31/32 | .9687 | 24.606 |
63/64 | .9844 | 25.003 |
1 | 1.000 | 25.400 |