Length unit guide

Kilometer

A complete practical guide to the kilometer: exact metric definition, symbol, relation to meters and miles, road-distance use, formulas, tables, and common mistakes.

A kilometer is a metric unit of length equal to 1,000 meters. It is used for road distances, geography, travel, maps, races, route planning, and large-scale distance measurement.

Quick facts

Unit name
kilometer
British spelling
kilometre
Symbol
km
Quantity
length
System
metric system
Exact relation
1 km = 1,000 m
Mile relation
1 km = 0.6213711922 mi
Centimeter relation
1 km = 100,000 cm

Visual scale

A kilometer is a large everyday distance: useful for towns, routes, races, and map scale.

1 m0.001 km
100 m0.1 km
1 km1,000 m

Definition and exact value

The prefix kilo- means one thousand, so one kilometer is exactly one thousand meters.

1 kilometer = 1,000 meters = 100,000 centimeters = 1,000,000 millimeters

Symbol and spelling

The standard symbol is km. Kilometer is common in US English; kilometre is common in British and international English. The symbol stays km.

How big is one kilometer?

A kilometer is suited for distance at neighborhood, road, race, and map scale. It is too large for object dimensions but natural for travel and outdoor routes.

Walking scale

A kilometer is often a short walk, depending on pace and terrain.

Road scale

Most countries use kilometers for road distances and speed limits.

Race scale

5 km and 10 km events are common running distances.

Kilometer vs mile

The kilometer is metric; the mile is customary and imperial. One mile equals exactly 1.609344 kilometers, so one kilometer is about 0.6213711922 miles.

1 km0.621371 mi
1 mile1.609344 km

Common uses

How kilometers are measured

Kilometers are usually measured by maps, odometers, GPS, measuring wheels, or surveyed coordinate systems rather than by handheld rulers.

Conversion formulas

meters = kilometers x 1,000
miles = kilometers / 1.609344
feet = kilometers x 3,280.839895

Kilometer conversion table

KilometersMetersMilesFeet
1 km1,000 m0.6213711922 mi3,280.839895 ft
5 km5,000 m3.106855961 mi16,404.19948 ft
10 km10,000 m6.213711922 mi32,808.39895 ft

Common mistakes

FAQ

How many meters are in one kilometer?

One kilometer equals exactly 1,000 meters.

How many miles are in one kilometer?

One kilometer equals about 0.6213711922 miles.

What is the symbol for kilometer?

The standard symbol is km.

Is kilometer metric?

Yes. The kilometer is a metric length unit based on the meter.