How to convert kilometers to millimeters
mm = km × 1,000,000Multiply the value in kilometers by 1,000,000. To go the other way, multiply by 0.000001 (or divide by 1,000,000).
A kilometer is larger than a millimeter: one kilometer contains 1,000,000 millimeters.
Worked examples
- 1 kilometer1 km × 1,000,000 = 1,000,000 mm
- 5 kilometers5 km × 1,000,000 = 5,000,000 mm
- 10 kilometers10 km × 1,000,000 = 10,000,000 mm
- 20 kilometers20 km × 1,000,000 = 20,000,000 mm
- 100 kilometers100 km × 1,000,000 = 100,000,000 mm
Kilometers to millimeters conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Kilometers (km) | Millimeters (mm) |
|---|---|
| 0.1 km | 100,000 mm |
| 0.25 km | 250,000 mm |
| 0.5 km | 500,000 mm |
| 1 km | 1,000,000 mm |
| 2 km | 2,000,000 mm |
| 3 km | 3,000,000 mm |
| 4 km | 4,000,000 mm |
| 5 km | 5,000,000 mm |
| 6 km | 6,000,000 mm |
| 7 km | 7,000,000 mm |
| 8 km | 8,000,000 mm |
| 9 km | 9,000,000 mm |
| 10 km | 10,000,000 mm |
| Kilometers (km) | Millimeters (mm) |
|---|---|
| 12 km | 12,000,000 mm |
| 15 km | 15,000,000 mm |
| 20 km | 20,000,000 mm |
| 25 km | 25,000,000 mm |
| 30 km | 30,000,000 mm |
| 40 km | 40,000,000 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 |
| 1,000 km | 1,000,000,000 mm |
About the units
Kilometer (km)
One thousand metres. Kilometres measure road distances and running races in most countries; a 10K race is 10 km, about 6.2 miles. One kilometer equals 1,000 meters (m).
Millimeter (mm)
One thousandth of a metre. Millimetres are the standard unit on engineering drawings, rulers and rainfall gauges; a credit card is about 0.76 mm thick. One millimeter equals 0.001 meters (m).
Frequently asked questions
How many millimeters are in one kilometer?
There are 1,000,000 millimeters in one kilometer, and this value is exact by definition.
How do I convert kilometers to millimeters?
Multiply the number of kilometers by 1,000,000. For example, 10 km × 1,000,000 = 10,000,000 mm.
How many kilometers are in one millimeter?
One millimeter equals 0.000001 kilometers. That is the reverse factor, 1 ÷ 1,000,000.
What is 10 kilometers in millimeters?
10 km = 10,000,000 mm.
Is this km to mm converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.