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.