Convert mm to km
1 mm = 1e-6 km · 1 km = 1000000 mm · Exact by definition
1 mm = 1e-6 km
The same value in other units
- centimetre
- 0.1 cm
- metre
- 0.001 m
- inch
- 0.0393701 in
- foot
- 0.00328084 ft
- yard
- 0.00109361 yd
- mile
- 6.21371e-7 mi
- nautical mile
- 5.39957e-7 nmi
Settings
Digits kept in the answer. Automatic keeps six, which hides floating-point noise without losing anything real.
Convert a whole list
Paste one conversion per line, written the way you would say it: "5 km to mi". Handy for a column copied out of a spreadsheet.
Length
mm to km: conversion table
| millimetre | kilometre |
|---|---|
| 1 mm | 1e-6 km |
| 2 mm | 2e-6 km |
| 3 mm | 3e-6 km |
| 5 mm | 5e-6 km |
| 10 mm | 1e-5 km |
| 20 mm | 2e-5 km |
| 25 mm | 2.5e-5 km |
| 50 mm | 5e-5 km |
| 100 mm | 0.0001 km |
| 250 mm | 0.00025 km |
| 500 mm | 0.0005 km |
| 1000 mm | 0.001 km |
| kilometre | millimetre |
|---|---|
| 1 km | 1000000 mm |
| 2 km | 2000000 mm |
| 3 km | 3000000 mm |
| 5 km | 5000000 mm |
| 10 km | 10000000 mm |
| 20 km | 20000000 mm |
| 25 km | 25000000 mm |
| 50 km | 50000000 mm |
| 100 km | 100000000 mm |
| 250 km | 250000000 mm |
| 500 km | 500000000 mm |
| 1000 km | 1000000000 mm |
How the conversion works
km = mm × 1e-6
Both units are defined exactly, so the precision of the mm to km result depends only on the number of decimal places you choose.
METHOD AND SOURCES
Where the conversion factors come from
Results are calculated from the unit definitions stored in the converter, not copied from a lookup table. For exact units, every value in the table follows from the same factor shown in the formula above.
- BIPM — SI Brochure
The official definitions of the International System of Units (SI).
- NIST SP 811 — Conversion factors
Conversion-factor tables for SI and non-SI units.
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