To convert kilometers to centimeters (km to cm), multiply by 100,000. 1 kilometer equals 100,000 cm, about 3 times as much as the height of the Eiffel Tower, in Paris.
| kilometers | centimeters |
|---|---|
| 1 kilometer | 100,000 cm |
| 2 kilometers | 200,000 cm |
| 5 kilometers | 500,000 cm |
| 10 kilometers | 1,000,000 cm |
| 25 kilometers | 2,500,000 cm |
| 50 kilometers | 5,000,000 cm |
| 100 kilometers | 10,000,000 cm |
| 250 kilometers | 25,000,000 cm |
| 500 kilometers | 50,000,000 cm |
| 1000 kilometers | 100,000,000 cm |
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.
Definition: 1/100 of a meter - the "centi" prefix doing the same job it does in "century" or "cent."
History: Introduced alongside the meter itself during the French Revolution's metric overhaul, the centimeter was designed from the start to be a convenient, everyday-sized subdivision - a meter is often too big and a millimeter too small for describing things like a person's height or a book's thickness.
Current use: Height, everyday object sizes, and fabric measurements across most of the world; also the standard unit doctors use internationally for body measurements.
The factor is 100000, which is derived rather than defined, so any decimal you see has been rounded somewhere.
No simple round multiplier is close enough to be useful, so this is one to look up rather than estimate. The exact factor is 100000.
Going the other way, one centimeter is 0.00001 km. Because the numbers get large quickly, a whole-number answer is almost always enough here: carrying decimals implies a precision your original measurement probably does not have.
To anchor the scale: 1 kilometer is about 100,000 cm.