Kilometer Converter

About Kilometers

The kilometer (km) is a unit of length in the metric system, equal to one thousand meters. It is commonly used for measuring longer distances such as:

• Distance between cities
• Road distances and travel measurements
• Hiking or walking routes
• Track and field events for longer distances
• Geographic features (mountain heights, river lengths)

To help visualize kilometers:

• Walking at an average pace of 5 km/h, you cover 1 km in about 12 minutes
• The distance from the Earth to the Moon is about 384,400 km
• The Earth’s circumference at the equator is approximately 40,075 km
• A marathon race is 42.195 km
• The typical cruising altitude of a commercial aircraft is 10-12 km
• The deepest point in the ocean (Mariana Trench) is about 11 km deep

The kilometer was introduced as part of the metric system during the French Revolution in the late 18th century. The prefix “kilo-” comes from the Greek word χίλιοι (chilioi), meaning “thousand.” While most countries around the world use kilometers for measuring distances, a few countries like the United States still primarily use miles for road distances and other everyday measurements.