Inch to mm Conversion Chart
Inch to mm conversion chart: fractions up to 2 inches in steps of 1/64 with millimetre and decimal inch values, and inch values for 1 to 100 mm.
For reference. Verify the application conditions and the applicable standard.
Columns
Advanced
Visible rows: 228
Scroll horizontally to see more columns.
| value | millimetresmm | decimal inchin |
|---|---|---|
| 1/64 in | 0.396875 | 0.0156250 |
| 1/32 in | 0.793750 | 0.0312500 |
| 3/64 in | 1.190625 | 0.0468750 |
| 1/16 in | 1.587500 | 0.0625000 |
| 5/64 in | 1.984375 | 0.0781250 |
| 3/32 in | 2.381250 | 0.0937500 |
| 7/64 in | 2.778125 | 0.1093750 |
| 1/8 in | 3.175000 | 0.1250000 |
| 9/64 in | 3.571875 | 0.1406250 |
| 5/32 in | 3.968750 | 0.1562500 |
| 11/64 in | 4.365625 | 0.1718750 |
| 3/16 in | 4.762500 | 0.1875000 |
| 13/64 in | 5.159375 | 0.2031250 |
| 7/32 in | 5.556250 | 0.2187500 |
| 15/64 in | 5.953125 | 0.2343750 |
| 1/4 in | 6.350000 | 0.2500000 |
| 17/64 in | 6.746875 | 0.2656250 |
| 9/32 in | 7.143750 | 0.2812500 |
| 19/64 in | 7.540625 | 0.2968750 |
| 5/16 in | 7.937500 | 0.3125000 |
| 21/64 in | 8.334375 | 0.3281250 |
| 11/32 in | 8.731250 | 0.3437500 |
| 23/64 in | 9.128125 | 0.3593750 |
| 3/8 in | 9.525000 | 0.3750000 |
| 25/64 in | 9.921875 | 0.3906250 |
| 13/32 in | 10.318750 | 0.4062500 |
| 27/64 in | 10.715625 | 0.4218750 |
| 7/16 in | 11.112500 | 0.4375000 |
| 29/64 in | 11.509375 | 0.4531250 |
| 15/32 in | 11.906250 | 0.4687500 |
| 31/64 in | 12.303125 | 0.4843750 |
| 1/2 in | 12.700000 | 0.5000000 |
| 33/64 in | 13.096875 | 0.5156250 |
| 17/32 in | 13.493750 | 0.5312500 |
| 35/64 in | 13.890625 | 0.5468750 |
| 9/16 in | 14.287500 | 0.5625000 |
| 37/64 in | 14.684375 | 0.5781250 |
| 19/32 in | 15.081250 | 0.5937500 |
| 39/64 in | 15.478125 | 0.6093750 |
| 5/8 in | 15.875000 | 0.6250000 |
| 41/64 in | 16.271875 | 0.6406250 |
| 21/32 in | 16.668750 | 0.6562500 |
| 43/64 in | 17.065625 | 0.6718750 |
| 11/16 in | 17.462500 | 0.6875000 |
| 45/64 in | 17.859375 | 0.7031250 |
| 23/32 in | 18.256250 | 0.7187500 |
| 47/64 in | 18.653125 | 0.7343750 |
| 3/4 in | 19.050000 | 0.7500000 |
| 49/64 in | 19.446875 | 0.7656250 |
| 25/32 in | 19.843750 | 0.7812500 |
| 51/64 in | 20.240625 | 0.7968750 |
| 13/16 in | 20.637500 | 0.8125000 |
| 53/64 in | 21.034375 | 0.8281250 |
| 27/32 in | 21.431250 | 0.8437500 |
| 55/64 in | 21.828125 | 0.8593750 |
| 7/8 in | 22.225000 | 0.8750000 |
| 57/64 in | 22.621875 | 0.8906250 |
| 29/32 in | 23.018750 | 0.9062500 |
| 59/64 in | 23.415625 | 0.9218750 |
| 15/16 in | 23.812500 | 0.9375000 |
| 61/64 in | 24.209375 | 0.9531250 |
| 31/32 in | 24.606250 | 0.9687500 |
| 63/64 in | 25.003125 | 0.9843750 |
| 1 in | 25.400000 | 1.0000000 |
| 65/64 in | 25.796875 | 1.0156250 |
| 33/32 in | 26.193750 | 1.0312500 |
| 67/64 in | 26.590625 | 1.0468750 |
| 17/16 in | 26.987500 | 1.0625000 |
| 69/64 in | 27.384375 | 1.0781250 |
| 35/32 in | 27.781250 | 1.0937500 |
| 71/64 in | 28.178125 | 1.1093750 |
| 9/8 in | 28.575000 | 1.1250000 |
| 73/64 in | 28.971875 | 1.1406250 |
| 37/32 in | 29.368750 | 1.1562500 |
| 75/64 in | 29.765625 | 1.1718750 |
| 19/16 in | 30.162500 | 1.1875000 |
| 77/64 in | 30.559375 | 1.2031250 |
| 39/32 in | 30.956250 | 1.2187500 |
| 79/64 in | 31.353125 | 1.2343750 |
| 5/4 in | 31.750000 | 1.2500000 |
| 81/64 in | 32.146875 | 1.2656250 |
| 41/32 in | 32.543750 | 1.2812500 |
| 83/64 in | 32.940625 | 1.2968750 |
| 21/16 in | 33.337500 | 1.3125000 |
| 85/64 in | 33.734375 | 1.3281250 |
| 43/32 in | 34.131250 | 1.3437500 |
| 87/64 in | 34.528125 | 1.3593750 |
| 11/8 in | 34.925000 | 1.3750000 |
| 89/64 in | 35.321875 | 1.3906250 |
| 45/32 in | 35.718750 | 1.4062500 |
| 91/64 in | 36.115625 | 1.4218750 |
| 23/16 in | 36.512500 | 1.4375000 |
| 93/64 in | 36.909375 | 1.4531250 |
| 47/32 in | 37.306250 | 1.4687500 |
| 95/64 in | 37.703125 | 1.4843750 |
| 3/2 in | 38.100000 | 1.5000000 |
| 97/64 in | 38.496875 | 1.5156250 |
| 49/32 in | 38.893750 | 1.5312500 |
| 99/64 in | 39.290625 | 1.5468750 |
| 25/16 in | 39.687500 | 1.5625000 |
| 101/64 in | 40.084375 | 1.5781250 |
| 51/32 in | 40.481250 | 1.5937500 |
| 103/64 in | 40.878125 | 1.6093750 |
| 13/8 in | 41.275000 | 1.6250000 |
| 105/64 in | 41.671875 | 1.6406250 |
| 53/32 in | 42.068750 | 1.6562500 |
| 107/64 in | 42.465625 | 1.6718750 |
| 27/16 in | 42.862500 | 1.6875000 |
| 109/64 in | 43.259375 | 1.7031250 |
| 55/32 in | 43.656250 | 1.7187500 |
| 111/64 in | 44.053125 | 1.7343750 |
| 7/4 in | 44.450000 | 1.7500000 |
| 113/64 in | 44.846875 | 1.7656250 |
| 57/32 in | 45.243750 | 1.7812500 |
| 115/64 in | 45.640625 | 1.7968750 |
| 29/16 in | 46.037500 | 1.8125000 |
| 117/64 in | 46.434375 | 1.8281250 |
| 59/32 in | 46.831250 | 1.8437500 |
| 119/64 in | 47.228125 | 1.8593750 |
| 15/8 in | 47.625000 | 1.8750000 |
| 121/64 in | 48.021875 | 1.8906250 |
| 61/32 in | 48.418750 | 1.9062500 |
| 123/64 in | 48.815625 | 1.9218750 |
| 31/16 in | 49.212500 | 1.9375000 |
| 125/64 in | 49.609375 | 1.9531250 |
| 63/32 in | 50.006250 | 1.9687500 |
| 127/64 in | 50.403125 | 1.9843750 |
| 2 in | 50.800000 | 2.0000000 |
| 1 mm | 1.000000 | 0.0393701 |
| 2 mm | 2.000000 | 0.0787402 |
| 3 mm | 3.000000 | 0.1181102 |
| 4 mm | 4.000000 | 0.1574803 |
| 5 mm | 5.000000 | 0.1968504 |
| 6 mm | 6.000000 | 0.2362205 |
| 7 mm | 7.000000 | 0.2755906 |
| 8 mm | 8.000000 | 0.3149606 |
| 9 mm | 9.000000 | 0.3543307 |
| 10 mm | 10.000000 | 0.3937008 |
| 11 mm | 11.000000 | 0.4330709 |
| 12 mm | 12.000000 | 0.4724409 |
| 13 mm | 13.000000 | 0.5118110 |
| 14 mm | 14.000000 | 0.5511811 |
| 15 mm | 15.000000 | 0.5905512 |
| 16 mm | 16.000000 | 0.6299213 |
| 17 mm | 17.000000 | 0.6692913 |
| 18 mm | 18.000000 | 0.7086614 |
| 19 mm | 19.000000 | 0.7480315 |
| 20 mm | 20.000000 | 0.7874016 |
| 21 mm | 21.000000 | 0.8267717 |
| 22 mm | 22.000000 | 0.8661417 |
| 23 mm | 23.000000 | 0.9055118 |
| 24 mm | 24.000000 | 0.9448819 |
| 25 mm | 25.000000 | 0.9842520 |
| 26 mm | 26.000000 | 1.0236220 |
| 27 mm | 27.000000 | 1.0629921 |
| 28 mm | 28.000000 | 1.1023622 |
| 29 mm | 29.000000 | 1.1417323 |
| 30 mm | 30.000000 | 1.1811024 |
| 31 mm | 31.000000 | 1.2204724 |
| 32 mm | 32.000000 | 1.2598425 |
| 33 mm | 33.000000 | 1.2992126 |
| 34 mm | 34.000000 | 1.3385827 |
| 35 mm | 35.000000 | 1.3779528 |
| 36 mm | 36.000000 | 1.4173228 |
| 37 mm | 37.000000 | 1.4566929 |
| 38 mm | 38.000000 | 1.4960630 |
| 39 mm | 39.000000 | 1.5354331 |
| 40 mm | 40.000000 | 1.5748031 |
| 41 mm | 41.000000 | 1.6141732 |
| 42 mm | 42.000000 | 1.6535433 |
| 43 mm | 43.000000 | 1.6929134 |
| 44 mm | 44.000000 | 1.7322835 |
| 45 mm | 45.000000 | 1.7716535 |
| 46 mm | 46.000000 | 1.8110236 |
| 47 mm | 47.000000 | 1.8503937 |
| 48 mm | 48.000000 | 1.8897638 |
| 49 mm | 49.000000 | 1.9291339 |
| 50 mm | 50.000000 | 1.9685039 |
| 51 mm | 51.000000 | 2.0078740 |
| 52 mm | 52.000000 | 2.0472441 |
| 53 mm | 53.000000 | 2.0866142 |
| 54 mm | 54.000000 | 2.1259843 |
| 55 mm | 55.000000 | 2.1653543 |
| 56 mm | 56.000000 | 2.2047244 |
| 57 mm | 57.000000 | 2.2440945 |
| 58 mm | 58.000000 | 2.2834646 |
| 59 mm | 59.000000 | 2.3228346 |
| 60 mm | 60.000000 | 2.3622047 |
| 61 mm | 61.000000 | 2.4015748 |
| 62 mm | 62.000000 | 2.4409449 |
| 63 mm | 63.000000 | 2.4803150 |
| 64 mm | 64.000000 | 2.5196850 |
| 65 mm | 65.000000 | 2.5590551 |
| 66 mm | 66.000000 | 2.5984252 |
| 67 mm | 67.000000 | 2.6377953 |
| 68 mm | 68.000000 | 2.6771654 |
| 69 mm | 69.000000 | 2.7165354 |
| 70 mm | 70.000000 | 2.7559055 |
| 71 mm | 71.000000 | 2.7952756 |
| 72 mm | 72.000000 | 2.8346457 |
| 73 mm | 73.000000 | 2.8740157 |
| 74 mm | 74.000000 | 2.9133858 |
| 75 mm | 75.000000 | 2.9527559 |
| 76 mm | 76.000000 | 2.9921260 |
| 77 mm | 77.000000 | 3.0314961 |
| 78 mm | 78.000000 | 3.0708661 |
| 79 mm | 79.000000 | 3.1102362 |
| 80 mm | 80.000000 | 3.1496063 |
| 81 mm | 81.000000 | 3.1889764 |
| 82 mm | 82.000000 | 3.2283465 |
| 83 mm | 83.000000 | 3.2677165 |
| 84 mm | 84.000000 | 3.3070866 |
| 85 mm | 85.000000 | 3.3464567 |
| 86 mm | 86.000000 | 3.3858268 |
| 87 mm | 87.000000 | 3.4251969 |
| 88 mm | 88.000000 | 3.4645669 |
| 89 mm | 89.000000 | 3.5039370 |
| 90 mm | 90.000000 | 3.5433071 |
| 91 mm | 91.000000 | 3.5826772 |
| 92 mm | 92.000000 | 3.6220472 |
| 93 mm | 93.000000 | 3.6614173 |
| 94 mm | 94.000000 | 3.7007874 |
| 95 mm | 95.000000 | 3.7401575 |
| 96 mm | 96.000000 | 3.7795276 |
| 97 mm | 97.000000 | 3.8188976 |
| 98 mm | 98.000000 | 3.8582677 |
| 99 mm | 99.000000 | 3.8976378 |
| 100 mm | 100.000000 | 3.9370079 |
Quick answers
- 1/4 in = 6.35 mm = 0.25 in. View in table
- 1/2 in = 12.7 mm = 0.5 in. View in table
- 3/4 in = 19.05 mm = 0.75 in. View in table
- 1 in = 25.4 mm = 1 in. View in table
- 10 mm = 10 mm = 0.3937008 in. View in table
- 25 mm = 25 mm = 0.984252 in. View in table
Conditions and notes
International inch. These are not nominal pipe sizes.
The international inch is exactly 25.4 mm. Multiply inches by 25.4 to get millimetres and divide for the reverse conversion. For example, 1/64 inch is exactly 0.396875 mm. Fractions run in 1/64 steps up to 2 inches. The final section gives reverse conversions from 1 to 100 mm in 1 mm steps. These are lengths, not nominal pipe or thread sizes.
Sources
This table is for preliminary reference. Check the applicable standard and product conditions before use.
- Source 1. SP 811:2008. Accessed: 2026-10-16
Data version: 2026-10-16