Kilometer

Definition: A kilometer (symbol: km) is a unit of length in the International System of Units (SI). One kilometer equals 0.6214 miles.

History/Origin: The prefix kilo- represents one thousand in the metric system, so one kilometer is 1,000 meters.

The kilometer’s definition relates to that of the meter, which is based on the distance light travels in 1/299,792,458 seconds. While this definition may change, the relationship between meters and kilometers remains fixed.

Current Use: The kilometer is widely used worldwide to measure distances between places on land.

However, countries like the United States and the United Kingdom still rely on miles. Although the UK officially uses the metric system, it retains miles for its road systems, unlike the US, where miles are the standard.

Mile

Definition: A mile (symbol: mi or m) is a length measurement unit in the imperial and US customary systems. It is defined as 5,280 feet, 1,760 yards, or exactly 1,609.344 meters.

History/Origin: The mile, originating from English units, predates the imperial and US customary systems. The abbreviation “mi” replaced “m” to avoid confusion with meters after the metric system’s adoption.

Defined as 5,280 feet (or 8 furlongs), the statute mile—distinct from the Roman mile (5,000 feet)—dates back to 1593 when England standardized the unit based on the furlong. Related units include the nautical mile (1.852 km), Italian mile (~1.852 km), and Chinese mile (500 m).

Current Use: Although most nations use kilometers for land distances, miles are still common in the United States, United Kingdom, Myanmar, Liberia, and some US or UK territories, reflecting their historical ties.

Kilometer to Mile Conversion Table

How to Convert Kilometer to Mile?

• 1 km = 0.6213711922 mi, mi(Int)
• 1 mi, mi(Int) = 1.609344 km

Example: Convert 15 km to mi, mi(Int):
15 km = 15 × 0.6213711922 mi, mi(Int) = 9.3205678836 mi, mi(Int).