To convert meters to kilometers (m to km), multiply by 0.001. 1 meter equals 0.001 km, about 1.4 times as much as a tennis racket.
| meters | kilometers |
|---|---|
| 1 meter | 0.001 km |
| 2 meters | 0.002 km |
| 5 meters | 0.005 km |
| 10 meters | 0.01 km |
| 25 meters | 0.025 km |
| 50 meters | 0.05 km |
| 100 meters | 0.1 km |
| 250 meters | 0.25 km |
| 500 meters | 0.5 km |
| 1000 meters | 1 km |
Definition: The base unit of length in the metric system - every other metric length (km, cm, mm) is just meters multiplied or divided by a power of ten.
History: Born out of the French Revolution's push to replace a chaotic patchwork of local, often royally-defined units with something rational and universal. In 1793, French scientists defined the meter as one ten-millionth of the distance from the North Pole to the Equator, measured along the meridian running through Paris - they actually sent surveyors out to physically measure the distance between Dunkirk and Barcelona to calculate it, a project that took years longer than planned. Today the meter is defined by something far more precise and impossible to argue with: the distance light travels in a tiny, fixed fraction of a second.
Current use: The foundation of virtually every length measurement outside the US - room dimensions, building heights, and race distances (measured in km) all build on it.
Definition: A kilometer is 1,000 meters - the "kilo" doing the same job it does in kilogram or kilobyte.
History: The meter itself was originally defined, back in 1793 during the French Revolution, as one ten-millionth of the distance from the North Pole to the equator. Today it's defined by how far light travels in a tiny fraction of a second instead - a far more precise anchor - but either way, a kilometer has always just meant a thousand of whatever "one meter" happens to be.
Current use: Nearly everywhere on Earth measures road distances, race lengths, and everyday travel in kilometers. The US remains one of the few holdouts still measuring road trips in miles.
The factor is 0.00100000, which is derived rather than defined, so any decimal you see has been rounded somewhere.
There is no tidy multiplier here, so work the other way: divide by 1,000 instead. That is the number worth remembering, because 1,000 meters make one kilometer exactly.
Going the other way, one kilometer is 1,000 m, which is usually the easier direction to work in. Because the forward factor is small, watch the decimal place rather than the digits: a factor-of-ten slip is the common error, not a rounding one.
To anchor the scale: 1,000 meters is about 1 km.