| 1 km = | 1000000000000000000 fm |
| 1 km = | 1000000000000000 pm |
| 1 km = | 10000000000000 Å |
| 1 km = | 1000000000000 nm |
| 1 km = | 1000000000 μm |
| 1 km = | 1000000 mm |
| 1 km = | 100000 cm |
| 1 km = | 39370.0787 in |
| 1 km = | 10000 dm |
| 1 km = | 3280.840 ft |
| 1 km = | 1093.613 yd |
| 1 km = | 1000 m |
| 1 km = | 0.621 mi |
| 1 km = | 0.540 n.m. |
| 1 km = | 0.207 lea |
| 1 km = | 0.00000000668 AU |
| 1 km = | 0.000000000000106 ly |
| 1 km = | 0.0000000000000324 pc |