Convert kilometer to millimeter
1 km = 1,000,000 mm
1 km = 1,000,000 mm
1 km in every length unit
| Planck length | 6.1871e+37 lP |
| femtometer | 1.0000e+18 fm |
| picometer | 1.0000e+15 pm |
| bohr radius | 18,897,000,000,000 a0 |
| angstrom | 10,000,000,000,000 Å |
| nanometer | 1,000,000,000,000 nm |
| micrometer | 1,000,000,000 μm |
| thou | 39,370,000 thou |
| point | 2,834,600 pt |
| millimeter | 1,000,000 mm |
| pica | 236,220 pc |
| centimeter | 100,000 cm |
| inch | 39,370 in |
| decimeter | 10,000 dm |
| hand | 9,842.5 hh |
| link | 4,971 li |
| foot | 3,280.8 ft |
| US survey foot | 3,280.8 ftUS |
| yard | 1,093.6 yd |
| meter | 1,000 m |
| fathom | 546.81 ftm |
| rod | 198.84 rd |
| chain | 49.71 ch |
| cable length | 5.3996 cb |
| furlong | 4.971 fur |
| kilometer | 1 km |
| mile | 0.62137 mi |
| nautical mile | 0.53996 nmi |
| league | 0.20712 lea |
| megameter | 0.001 Mm |
| Earth radius | 0.00015696 REarth |
| light-second | 0.0000033356 ls |
| lunar distance | 0.0000026015 LD |
| solar radius | 0.0000014374 Rsun |
| light-minute | 5.5594e-08 lmin |
| astronomical unit | 6.6846e-09 AU |
| light-year | 1.0570e-13 ly |
| parsec | 3.2408e-14 pc |
| kiloparsec | 3.2408e-17 kpc |
| megaparsec | 3.2408e-20 Mpc |
| gigaparsec | 3.2408e-23 Gpc |
How the conversion works
Multiply by 1,000,000 to go from kilometer 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 kilometer — 1 mm = 0.000001 km.
kilometer to millimeter — common values
| 1 km | 1,000,000 mm |
| 2 km | 2,000,000 mm |
| 3 km | 3,000,000 mm |
| 5 km | 5,000,000 mm |
| 10 km | 10,000,000 mm |
| 15 km | 15,000,000 mm |
| 20 km | 20,000,000 mm |
| 25 km | 25,000,000 mm |
| 50 km | 50,000,000 mm |
| 75 km | 75,000,000 mm |
| 100 km | 100,000,000 mm |
| 250 km | 250,000,000 mm |
| 500 km | 500,000,000 mm |
| 1000 km | 1,000,000,000 mm |