Length Converter
Convert length and distance between metric, US/imperial, nautical and astronomical units, from nanometres to light-years.
Your inputs
Results
10 km in mi
6.2137119224 mi
- Conversion type
- Exact (from defined constants; display rounded to 12 significant figures)
- 1 km =
- 0.621371192237 mi
✓Exact calculation — rounded only for display
| Unit | Value |
|---|---|
| Nanometre (nm) | 10,000,000,000,000 |
| Micrometre (µm) | 10,000,000,000 |
| Millimetre (mm) | 10,000,000 |
| Centimetre (cm) | 1,000,000 |
| Decimetre (dm) | 100,000 |
| Metre (m) | 10,000 |
| Kilometre (km) | 10 |
| Thou / mil (mil) | 393,700,787.402 |
| Inch (in) | 393,700.787402 |
| Foot (ft) | 32,808.3989501 |
| Yard (yd) | 10,936.1329834 |
| Mile (international) (mi) | 6.2137119224 |
| Nautical mile (nmi) | 5.3995680346 |
| Furlong (fur) | 49.709695379 |
| Chain (ch) | 497.09695379 |
| Astronomical unit (au) | 6.68459E-8 |
| Light-year (Julian) (ly) | 1.057E-12 |
| Parsec (pc) | 3.24078E-13 |
What this calculator does
Convert between millimetres, metres, kilometres, inches, feet, yards, miles, nautical miles, furlongs and astronomical distances.
Formula and method
value in metres = value × factor(from); result = metres ÷ factor(to). Exact definitions: 1 in = 0.0254 m, 1 ft = 0.3048 m, 1 mi = 1609.344 m, 1 nmi = 1852 m.
Worked example
Calculated by this tool with its default inputs:
Inputs
- Value: 10
- From: Kilometre (km)
- To: Mile (international) (mi)
Results
- 10 km in mi: 6.2137119224 mi
- Conversion type: Exact (from defined constants; display rounded to 12 significant figures)
- 1 km =: 0.621371192237 mi
How to read the results
The full table shows the value in every unit at once.
Assumptions and limitations
- The international mile and foot are used; the old US survey foot is not.
- Constants follow NIST SP 811 and the SI Brochure. Conversions marked exact follow from defined values; display is rounded to 12 significant figures.
Questions
How many kilometres in a mile?
Exactly 1.609344.
Sources
Methodology and verification
- Result type
- Exact mathematical calculation (rounded only for display)
- Formula version
- 1.0
- Automated verification
- 9 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy