km
What is a Kilometer?
Length Unit
Definition
A kilometer is a unit of length equal to 1,000 meters. It is commonly used to measure distances between geographical locations.
Popular Kilometer Conversions
Most common conversions from Kilometers
History
The kilometer was introduced as part of the metric system in France in 1795. The prefix 'kilo' comes from the Greek word 'chilioi' meaning thousand.
Common Uses
- Road distances and speed limits in most countries
- Marathon and long-distance running (42.195 km)
- Geographic distances between cities
- Aviation altitude measurements
Fun Facts
A marathon is exactly 42.195 kilometers
The circumference of Earth is approximately 40,075 kilometers
Light travels about 300,000 kilometers per second
All Kilometer Conversions
Kilometers to Meters km → m Kilometers to Centimeters km → cm Kilometers to Millimeters km → mm Kilometers to Miles km → mi Kilometers to Yards km → yd Kilometers to Feet km → ft Kilometers to Inches km → in Kilometers to Nautical Miles km → nmi Kilometers to Micrometers km → μm Kilometers to Nanometers km → nm Kilometers to Light Years km → ly