KM to Miles Converter
Convert kilometers to miles and miles to kilometers instantly. Also shows nautical miles, the conversion formula, and a reference table.
Enter a value in either field to convert between kilometers and miles.
Common conversions
| Kilometers | Miles | Nautical Miles |
|---|---|---|
| 1 | 0.6214 | 0.54 |
| 5 | 3.1069 | 2.6998 |
| 10 | 6.2137 | 5.3996 |
| 21.0975 | 13.1094 | 11.3917 |
| 42.195 | 26.2188 | 22.7835 |
| 50 | 31.0686 | 26.9978 |
| 100 | 62.1371 | 53.9957 |
| 160.934 | 99.9998 | 86.8974 |
| 500 | 310.6856 | 269.9784 |
| 1000 | 621.3712 | 539.9568 |
About KM to Miles Converter
This KM to Miles Converter provides instant, bidirectional conversion between kilometers and miles. Enter a value in either field and the equivalent measurement updates as you type. The tool also displays the nautical miles equivalent for maritime and aviation use cases.
How the Conversion Works
One mile is defined as exactly 1,609.344 meters, giving a conversion factor of approximately 0.621371 miles per kilometer. To convert kilometers to miles, multiply by 0.621371. To go the other direction, multiply miles by 1.609344. These factors are exact by international agreement.
Nautical Miles Display
For each conversion, the tool also shows the value in nautical miles. One nautical mile equals exactly 1,852 meters. This unit is standard in aviation and maritime navigation because it corresponds to one minute of latitude, making chart-based navigation simpler.
Quick Reference Table
A table of common distances and their equivalents is included below the converter. It covers values useful for running, driving, and general distance estimation so you can get a fast answer without entering anything.
Privacy and Performance
All calculations run entirely in your browser. No data is sent to any server, and the tool works offline once the page has loaded. Results update with each keystroke for a responsive experience.
Frequently Asked Questions
How do you convert kilometers to miles?
Multiply the kilometer value by 0.621371. For example, 10 km multiplied by 0.621371 equals approximately 6.2137 miles. The factor comes from the definition of one mile as exactly 1,609.344 meters.
How do you convert miles to kilometers?
Multiply the mile value by 1.609344. For example, 5 miles multiplied by 1.609344 equals exactly 8.04672 kilometers.
What is a nautical mile and how does it differ from a regular mile?
A nautical mile equals exactly 1,852 meters (about 1.15078 statute miles). It is based on one minute of arc of latitude at the equator and is used in aviation and maritime navigation. A statute (regular) mile is 1,609.344 meters.
Is a quick estimate possible without a calculator?
Yes. A popular shortcut uses the Fibonacci sequence. Consecutive Fibonacci numbers approximate the km-to-miles ratio because the golden ratio (about 1.618) is close to the conversion factor (1.609). For example, 8 km is roughly 5 miles, and 13 km is roughly 8 miles.
Where is each unit commonly used?
Kilometers are the standard distance unit in most countries worldwide and in scientific contexts. Miles are used in the United States, the United Kingdom (for road distances), and a few other nations. Nautical miles are used globally in shipping and aviation.