Kilometers to Miles
Convert kilometers to miles instantly. Free, fast, no signup.
How to use this tool
- Enter kilometers in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your miles and the full breakdown beneath it.
Convert kilometers to miles instantly. Free, fast, no signup.
Formula
Miles = Kilometers × 0.621371192237334
Equivalently: Miles = Kilometers ÷ 1.609344
The factor 0.6214 (rounded) comes from the definition that 1 mile = 1.609344 km exactly.
How it works
Multiply the kilometer value by approximately 0.621371 to obtain statute miles. The exact factor derives from the defined value of the international mile (1609.344 meters), so the only imprecision in any result is from display rounding.
Common mistake: mixing up statute miles (used for road distances) with nautical miles (1 nautical mile = 1.852 km). Using the statute-mile factor for nautical-mile conversions produces errors of about 15%, which is critical in aviation and marine navigation.
Worked example
Convert 1 kilometer to miles
- Start with the input: 1 kilometer.
- Apply the formula: Miles = 1 × 0.621371192237334.
- Round to four decimal places: 0.6214.
1 kilometer = 0.6214 miles
Common mistakes to avoid
- Multiplying by 1.609 instead of dividing (or multiplying by 0.6214) -- that converts miles to kilometers, not km to miles.
- Using the rough approximation of 0.6 instead of 0.6214, which understates distance by about 3.4% -- noticeable over marathon-length runs.
- Confusing statute miles with nautical miles -- 1 nautical mile = 1.852 km, so the factor 0.6214 does not apply to nautical contexts.
Key terms
- Kilometer (km)
- A metric unit of length equal to 1,000 meters, used for road distances and geographic measurements in most countries.
- Statute mile
- The standard land mile used in the United States and United Kingdom, equal to exactly 1,609.344 meters or 5,280 feet.
- Nautical mile
- A unit of length used in maritime and aviation contexts, equal to exactly 1,852 meters — distinct from the statute mile.
- International mile
- The precise definition of the mile adopted in 1959, fixing 1 mile = 1,609.344 meters and enabling exact metric conversions.
Frequently asked questions
- How do I convert kilometers to miles?
- Multiply the number of kilometers by 0.621371 to get miles.