Inch (in)
The inch (in) is exactly 2.54 centimetres. It is 1/12 of a foot.
Symbol: in
Quantity: length and distance
SI relation: 1 in = 0.0254 m (exact)
Derivation: 1 in = 2.54 cm = 0.0254 m (exact)
Exact: yes, by definition
Reference conditions. The international yard and pound agreement (1959) fixed 1 yard = 0.9144 m exactly, so the inch, foot and mile are exact.
Typical uses
- Screen and TV sizes (diagonal)
- US engineering drawings, pipe and fastener sizes
- Person height together with feet
Convert inches to other units
| Conversion | 1 in equals | Reverse |
|---|---|---|
| inch to meter | 0.0254 m | meter to inch |
| inch to kilometer | 0.0000254 km | kilometer to inch |
| inch to centimeter | 2.54 cm | centimeter to inch |
| inch to millimeter | 25.4 mm | millimeter to inch |
| inch to mile | 0.00001578282828 mi | mile to inch |
| inch to foot | 0.08333333333 ft | foot to inch |
| inch to micrometer | 25400 µm | micrometer to inch |
| inch to nanometer | 25400000 nm | nanometer to inch |
| inch to yard | 0.02777777778 yd | yard to inch |
| inch to nautical mile | 0.00001371490281 nmi | nautical mile to inch |
| inch to angstrom | 254000000 Å | angstrom to inch |
| inch to mil | 1000 mil | mil to inch |
Open the Length Converter to convert any value between all units.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "inch (in)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Inch (in). Retrieved October 17, 2026, from https://scientificconverters.com/units/inch/
IEEE
Scientific Converters, "Inch (in)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/inch/