| inch | 1 in | 2 in | 3 in | 4 in | 5 in | 6 in | 7 in | 8 in | 9 in | 10 in | 11 in | 12 in | 13 in | 14 in | 15 in | 16 in | 17 in | 18 in | 19 in | 20 in | 21 in | 22 in | 23 in | 24 in | 25 in | 26 in | 27 in | 28 in | 29 in | 30 in | 31 in | 32 in | 33 in | 34 in | 35 in | 36 in | 37 in | 38 in | 39 in | 40 in | 41 in | 42 in | 43 in | 44 in | 45 in | 46 in | 47 in | 48 in | 49 in | 50 in | 51 in | 52 in | 53 in | 54 in | 55 in | 56 in | 57 in | 58 in | 59 in | 60 in | 61 in | 62 in | 63 in | 64 in | 65 in | 66 in | 67 in | 68 in | 69 in | 70 in | 71 in | 72 in | 73 in | 74 in | 75 in | 76 in | 77 in | 78 in | 79 in | 80 in | 81 in | 82 in | 83 in | 84 in | 85 in | 86 in | 87 in | 88 in | 89 in | 90 in | 91 in | 92 in | 93 in | 94 in | 95 in | 96 in | 97 in | 98 in | 99 in | 100 in |
| thou | 1 000 th | 2 000 th | 3 000 th | 4 000 th | 5 000 th | 6 000 th | 7 000 th | 8 000 th | 9 000 th | 10 000 th | 11 000 th | 12 000 th | 13 000 th | 14 000 th | 15 000 th | 16 000 th | 17 000 th | 18 000 th | 19 000 th | 20 000 th | 21 000 th | 22 000 th | 23 000 th | 24 000 th | 25 000 th | 26 000 th | 27 000 th | 28 000 th | 29 000 th | 30 000 th | 31 000 th | 32 000 th | 33 000 th | 34 000 th | 35 000 th | 36 000 th | 37 000 th | 38 000 th | 39 000 th | 40 000 th | 41 000 th | 42 000 th | 43 000 th | 44 000 th | 45 000 th | 46 000 th | 47 000 th | 48 000 th | 49 000 th | 50 000 th | 51 000 th | 52 000 th | 53 000 th | 54 000 th | 55 000 th | 56 000 th | 57 000 th | 58 000 th | 59 000 th | 60 000 th | 61 000 th | 62 000 th | 63 000 th | 64 000 th | 65 000 th | 66 000 th | 67 000 th | 68 000 th | 69 000 th | 70 000 th | 71 000 th | 72 000 th | 73 000 th | 74 000 th | 75 000 th | 76 000 th | 77 000 th | 78 000 th | 79 000 th | 80 000 th | 81 000 th | 82 000 th | 83 000 th | 84 000 th | 85 000 th | 86 000 th | 87 000 th | 88 000 th | 89 000 th | 90 000 th | 91 000 th | 92 000 th | 93 000 th | 94 000 th | 95 000 th | 96 000 th | 97 000 th | 98 000 th | 99 000 th | 100 000 th |
The inch (abbreviation: in or ″) is a unit of length in the (British) imperial and United States customary systems of measurement now formally equal to 1⁄36 yard but usually understood as 1⁄12 of a foot. Derived from the Roman uncia ("twelfth"), inch is also sometimes used to translate related units in other measurement systems, usually understood as deriving from the width of the human thumb.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| inch | in | ≡ 2.54 cm ≡ 1⁄36 yd ≡ 1⁄12 ft | ≡ 0.0254 m | Imperial/US |
| inches | thous | inches | thous |
|---|---|---|---|
| 1 | ≡ 1000 | 4 | ≡ 4000 |
| 1.5 | ≡ 1500 | 4.5 | ≡ 4500 |
| 2 | ≡ 2000 | 5 | ≡ 5000 |
| 2.5 | ≡ 2500 | 5.5 | ≡ 5500 |
| 3 | ≡ 3000 | 6 | ≡ 6000 |
A thousandth of an inch is a derived unit of length in an inch-based system of units. Equal to 0.001 inches, it is normally referred to as a thou /ˈθaʊ/, a thousandth, or (particularly in the United States) a mil.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| thou | th | ≡ 1×10−3 in | ≡ 2.54×10−5 m | Imperial/US |
| thous | inches | thous | inches |
|---|---|---|---|
| 1 | ≡ 0.001 | 4 | ≡ 0.004 |
| 1.5 | ≡ 0.0015 | 4.5 | ≡ 0.0045 |
| 2 | ≡ 0.002 | 5 | ≡ 0.005 |
| 2.5 | ≡ 0.0025 | 5.5 | ≡ 0.0055 |
| 3 | ≡ 0.003 | 6 | ≡ 0.006 |
| inches | thous |
|---|---|
| 1 | ≡ 1 000 |
| 0.001 | ≡ 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 …) |