Convert inch to millimeter
1 in = 25.4 mm
sig figs
1 in = 25.4 mm
1 in in every length unit
| Planck length | 1.57e+33 lP |
| femtometer | 25,400,000,000,000 fm |
| picometer | 25,400,000,000 pm |
| bohr radius | 480,000,000 a0 |
| angstrom | 254,000,000 Å |
| nanometer | 25,400,000 nm |
| micrometer | 25,400 μm |
| thou | 1,000 thou |
| point | 72 pt |
| millimeter | 25.4 mm |
| pica | 6 pc |
| centimeter | 2.54 cm |
| inch | 1 in |
| decimeter | 0.254 dm |
| hand | 0.25 hh |
| link | 0.126 li |
| foot | 0.0833 ft |
| US survey foot | 0.0833 ftUS |
| yard | 0.0278 yd |
| meter | 0.0254 m |
| fathom | 0.0139 ftm |
| rod | 0.00505 rd |
| chain | 0.00126 ch |
| cable length | 0.000137 cb |
| furlong | 0.000126 fur |
| kilometer | 0.0000254 km |
| mile | 0.0000158 mi |
| nautical mile | 0.0000137 nmi |
| league | 0.00000526 lea |
| megameter | 2.54e-08 Mm |
| Earth radius | 3.99e-09 REarth |
| light-second | 8.47e-11 ls |
| lunar distance | 6.61e-11 LD |
| solar radius | 3.65e-11 Rsun |
| light-minute | 1.41e-12 lmin |
| astronomical unit | 1.70e-13 AU |
| light-year | 2.68e-18 ly |
| parsec | 8.23e-19 pc |
| kiloparsec | 8.23e-22 kpc |
| megaparsec | 8.23e-25 Mpc |
| gigaparsec | 8.23e-28 Gpc |
How the conversion works
Multiply by 25.4 to go from inch to millimeter, or divide by it to go back. Every conversion on this site routes through the SI value (m) rather than a table of pairwise factors, so a round-trip returns exactly what you started with.
Going the other way? millimeter to inch: 1 mm = 0.03937007874 in.
inch to millimeter: common values
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 50 in | 1,270 mm |
| 75 in | 1,905 mm |
| 100 in | 2,540 mm |
| 250 in | 6,350 mm |
| 500 in | 12,700 mm |
| 1000 in | 25,400 mm |