Meters to Kilometers
Convert meters (m) to kilometers (km). Both measure distance and dimension, and the conversion comes up in construction, navigation, sports work.
The Formula
``
kilometers = meters × 0.001
meters = kilometers × 1000
`
One meter is 0.001 kilometers, and one kilometer is 1,000 meters.
Conversion Table
| Meters | Kilometers |
|---|---|
| 1 m | 0.001 km |
| 2 m | 0.002 km |
| 5 m | 0.005 km |
| 10 m | 0.01 km |
| 25 m | 0.025 km |
| 50 m | 0.05 km |
| 100 m | 0.1 km |
| 500 m | 0.5 km |
| 1,000 m | 1 km |
The Other Direction
| Kilometers | Meters |
|---|---|
| 1 km | 1,000 m |
| 2 km | 2,000 m |
| 5 km | 5,000 m |
| 10 km | 10,000 m |
| 25 km | 25,000 m |
| 50 km | 50,000 m |
| 100 km | 100,000 m |
| 500 km | 500,000 m |
| 1,000 km | 1,000,000 m |
What Each Unit Is
Meters (m) — the distance light travels in a vacuum in 1/299,792,458 of a second — the SI base unit of length. Defined in 1793 as one ten-millionth of the distance from the equator to the North Pole, then by a platinum bar, and since 1983 by the speed of light.
Kilometers (km) — 1,000 metres. The metric system’s road-scale unit, adopted across most of the world in the 19th century.
A Sense of Scale
A doorway is about 2 m tall- An Olympic pool is 50 m
- A city block is 80–120 m
- A 20-minute walk covers about 1.5 km
- A marathon is 42.195 km
- A cruising airliner flies at 11 km
Precision
The factor 0.001 is exact by international agreement, not a rounded approximation. Any imprecision in a result comes from your input, not the conversion.
In Code
`javascript
const meterToKilometer = (value) => value * 0.001;
``
Where This Conversion Comes Up
- Construction
- Navigation
- Sports
- Sewing
- Mapping
How Many Decimals Do You Need?
Rounding the factor costs accuracy, and how much depends on the factor. Converting 137 m with the factor truncated at each decimal place:
| Decimals kept | Factor | 137 m becomes | Error |
|---|---|---|---|
| 0 | 0 | 0 | 100.0000% |
| 1 | 0 | 0 | 100.0000% |
| 2 | 0 | 0 | 100.0000% |
| 3 | 0.001 | 0.137 | — |
| 4 | 0.001 | 0.137 | — |
The right number of significant figures is set by your input, not by the converter. If you measured meters to three significant figures, the answer in kilometers is only good to three — writing more digits claims precision the measurement never had.