Convert inch to millimeter
1 in = 25.4 mm
1 in = 25.4 mm
1 in in every length unit
| Planck length | 1.5715e+33 lP |
| femtometer | 25,400,000,000,000 fm |
| picometer | 25,400,000,000 pm |
| bohr radius | 479,990,000 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 | 0.12626 li |
| foot | 0.083333 ft |
| US survey foot | 0.083333 ftUS |
| yard | 0.027778 yd |
| meter | 0.0254 m |
| fathom | 0.013889 ftm |
| rod | 0.0050505 rd |
| chain | 0.0012626 ch |
| cable length | 0.00013715 cb |
| furlong | 0.00012626 fur |
| kilometer | 0.0000254 km |
| mile | 0.000015783 mi |
| nautical mile | 0.000013715 nmi |
| league | 0.0000052609 lea |
| megameter | 2.5400e-08 Mm |
| Earth radius | 3.9868e-09 REarth |
| light-second | 8.4725e-11 ls |
| lunar distance | 6.6077e-11 LD |
| solar radius | 3.6510e-11 Rsun |
| light-minute | 1.4121e-12 lmin |
| astronomical unit | 1.6979e-13 AU |
| light-year | 2.6848e-18 ly |
| parsec | 8.2316e-19 pc |
| kiloparsec | 8.2316e-22 kpc |
| megaparsec | 8.2316e-25 Mpc |
| gigaparsec | 8.2316e-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 |