Decimal Equivalents Card

Pocket-card decimal equivalents: every 64th of an inch from 1/64″ to 1″ with decimal inches and exact millimetres — sized to print on one page.


Updated August 20, 2026

This is the card machinists tape inside the toolbox lid: all 64 sixty-fourths of an inch, each reduced to lowest terms, with its decimal-inch equivalent to four places and its millimetre equivalent to three. Nothing here is transcribed from another chart — the rows are generated from the same computed constant as the full fraction–decimal–mm reference chart, where 1 in = 25.4 mm exactly by the 1959 international inch definition.

Print it with the button below — the layout is tuned to fit a single letter page with margins you can trim to pocket size. For the two-table wall-chart version with FAQs and mental-math anchors, see the full reference chart linked underneath.

Decimal Equivalents — 1/64″ to 1″

Fraction (in)Decimal (in)mm
1/64″0.01560.397
1/32″0.03130.794
3/64″0.04691.191
1/16″0.06251.588
5/64″0.07811.984
3/32″0.09382.381
7/64″0.10942.778
1/8″0.12503.175
9/64″0.14063.572
5/32″0.15633.969
11/64″0.17194.366
3/16″0.18754.763
13/64″0.20315.159
7/32″0.21885.556
15/64″0.23445.953
1/4″0.25006.350
17/64″0.26566.747
9/32″0.28137.144
19/64″0.29697.541
5/16″0.31257.938
21/64″0.32818.334
11/32″0.34388.731
23/64″0.35949.128
3/8″0.37509.525
25/64″0.39069.922
13/32″0.406310.319
27/64″0.421910.716
7/16″0.437511.113
29/64″0.453111.509
15/32″0.468811.906
31/64″0.484412.303
1/2″0.500012.700
33/64″0.515613.097
17/32″0.531313.494
35/64″0.546913.891
9/16″0.562514.288
37/64″0.578114.684
19/32″0.593815.081
39/64″0.609415.478
5/8″0.625015.875
41/64″0.640616.272
21/32″0.656316.669
43/64″0.671917.066
11/16″0.687517.463
45/64″0.703117.859
23/32″0.718818.256
47/64″0.734418.653
3/4″0.750019.050
49/64″0.765619.447
25/32″0.781319.844
51/64″0.796920.241
13/16″0.812520.638
53/64″0.828121.034
27/32″0.843821.431
55/64″0.859421.828
7/8″0.875022.225
57/64″0.890622.622
29/32″0.906323.019
59/64″0.921923.416
15/16″0.937523.813
61/64″0.953124.209
31/32″0.968824.606
63/64″0.984425.003
1″1.000025.400

Exact by definition: 1 in = 25.4 mm. Decimal shown to 4 places, mm to 3.

Sources

  • International yard and pound agreement (1959): 1 in = 25.4 mm exactly, as codified in NIST SP 811 and the Federal Register notice of July 1, 1959 — every cell is computed from this definition, none transcribed

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