| metric inch | 1 in (metric) | 2 in (metric) | 3 in (metric) | 4 in (metric) | 5 in (metric) | 6 in (metric) | 7 in (metric) | 8 in (metric) | 9 in (metric) | 10 in (metric) | 11 in (metric) | 12 in (metric) | 13 in (metric) | 14 in (metric) | 15 in (metric) | 16 in (metric) | 17 in (metric) | 18 in (metric) | 19 in (metric) | 20 in (metric) | 21 in (metric) | 22 in (metric) | 23 in (metric) | 24 in (metric) | 25 in (metric) | 26 in (metric) | 27 in (metric) | 28 in (metric) | 29 in (metric) | 30 in (metric) | 31 in (metric) | 32 in (metric) | 33 in (metric) | 34 in (metric) | 35 in (metric) | 36 in (metric) | 37 in (metric) | 38 in (metric) | 39 in (metric) | 40 in (metric) | 41 in (metric) | 42 in (metric) | 43 in (metric) | 44 in (metric) | 45 in (metric) | 46 in (metric) | 47 in (metric) | 48 in (metric) | 49 in (metric) | 50 in (metric) | 51 in (metric) | 52 in (metric) | 53 in (metric) | 54 in (metric) | 55 in (metric) | 56 in (metric) | 57 in (metric) | 58 in (metric) | 59 in (metric) | 60 in (metric) | 61 in (metric) | 62 in (metric) | 63 in (metric) | 64 in (metric) | 65 in (metric) | 66 in (metric) | 67 in (metric) | 68 in (metric) | 69 in (metric) | 70 in (metric) | 71 in (metric) | 72 in (metric) | 73 in (metric) | 74 in (metric) | 75 in (metric) | 76 in (metric) | 77 in (metric) | 78 in (metric) | 79 in (metric) | 80 in (metric) | 81 in (metric) | 82 in (metric) | 83 in (metric) | 84 in (metric) | 85 in (metric) | 86 in (metric) | 87 in (metric) | 88 in (metric) | 89 in (metric) | 90 in (metric) | 91 in (metric) | 92 in (metric) | 93 in (metric) | 94 in (metric) | 95 in (metric) | 96 in (metric) | 97 in (metric) | 98 in (metric) | 99 in (metric) | 100 in (metric) |
| millimeter | 0.4 mm | 0.8 mm | 1.2 mm | 1.6 mm | 2 mm | 2.4 mm | 2.8 mm | 3.2 mm | 3.6 mm | 4 mm | 4.4 mm | 4.8 mm | 5.2 mm | 5.6 mm | 6 mm | 6.4 mm | 6.8 mm | 7.2 mm | 7.6 mm | 8 mm | 8.4 mm | 8.8 mm | 9.2 mm | 9.6 mm | 10 mm | 10.4 mm | 10.8 mm | 11.2 mm | 11.6 mm | 12 mm | 12.4 mm | 12.8 mm | 13.2 mm | 13.6 mm | 14 mm | 14.4 mm | 14.8 mm | 15.2 mm | 15.6 mm | 16 mm | 16.4 mm | 16.8 mm | 17.2 mm | 17.6 mm | 18 mm | 18.4 mm | 18.8 mm | 19.2 mm | 19.6 mm | 20 mm | 20.4 mm | 20.8 mm | 21.2 mm | 21.6 mm | 22 mm | 22.4 mm | 22.8 mm | 23.2 mm | 23.6 mm | 24 mm | 24.4 mm | 24.8 mm | 25.2 mm | 25.6 mm | 26 mm | 26.4 mm | 26.8 mm | 27.2 mm | 27.6 mm | 28 mm | 28.4 mm | 28.8 mm | 29.2 mm | 29.6 mm | 30 mm | 30.4 mm | 30.8 mm | 31.2 mm | 31.6 mm | 32 mm | 32.4 mm | 32.8 mm | 33.2 mm | 33.6 mm | 34 mm | 34.4 mm | 34.8 mm | 35.2 mm | 35.6 mm | 36 mm | 36.4 mm | 36.8 mm | 37.2 mm | 37.6 mm | 38 mm | 38.4 mm | 38.8 mm | 39.2 mm | 39.6 mm | 40 mm |
A metric inch is a nickname for a preferred 1⁄4 subdivision of an ISO 2848 basic module, or 1⁄12 of a metric foot measuring 25 millimetres (0.984 in). A metric inch is 0.4 millimetres (0.016 in) shorter than an inch.
The term was similarly used to refer to the historical Soviet Bloc practice of spacing integrated circuit pins at 1⁄10 of a 25 mm "metric inch" length, instead of the western practice of 1⁄10 of an imperial inch.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| metric inch | in (metric) | = 0.016 in | = 0.0004 m | Metric system SI |
| metric inches | millimeters | metric inches | millimeters |
|---|---|---|---|
| 1 | = 0.4 | 4 | = 1.6 |
| 1.5 | = 0.6 | 4.5 | = 1.8 |
| 2 | = 0.8 | 5 | = 2 |
| 2.5 | = 1 | 5.5 | = 2.2 |
| 3 | = 1.2 | 6 | = 2.4 |
The millimetre (International spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore there are thousand millimetres in a metre. There are ten millimetres in a centimetre.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| millimeter | mm | ≡ 1×10-3 m ≡ 0.001 m | ≡ 1×10-3 m ≡ 0.001 m | Metric system SI |
| millimeters | metric inches | millimeters | metric inches |
|---|---|---|---|
| 1 | = 2.5 | 4 | = 10 |
| 1.5 | = 3.75 | 4.5 | = 11.25 |
| 2 | = 5 | 5 | = 12.5 |
| 2.5 | = 6.25 | 5.5 | = 13.75 |
| 3 | = 7.5 | 6 | = 15 |
| metric inches | millimeters |
|---|---|
| 1 | = 0.4 |
| 2.5 | = 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |