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Kilometers to Miles (km to mi)
Convert kilometers to miles: 1 km = 0.621371 mi. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.
Formula
1 km = 0.621371 mi
miles = kilometers × 0.6213711922 — reverse: kilometers = miles × 1.609344
The factor is derived from the SI definitions of both units (base unit: m) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.
Worked examples
- 5 km = 3.10686 mi
- 12.5 km = 7.76714 mi
- 100 km = 62.1371 mi
Kilometers to miles conversion table
| Kilometers (km) | Miles (mi) |
|---|---|
| 1 | 0.621371 |
| 2 | 1.24274 |
| 3 | 1.86411 |
| 4 | 2.48548 |
| 5 | 3.10686 |
| 6 | 3.72823 |
| 7 | 4.3496 |
| 8 | 4.97097 |
| 9 | 5.59234 |
| 10 | 6.21371 |
| 15 | 9.32057 |
| 20 | 12.4274 |
| 25 | 15.5343 |
| 30 | 18.6411 |
| 40 | 24.8548 |
| 50 | 31.0686 |
| 75 | 46.6028 |
| 100 | 62.1371 |
| 200 | 124.274 |
| 250 | 155.343 |
| 500 | 310.686 |
| 1000 | 621.371 |
FAQ
How many miles are in one kilometer?
1 km = 0.621371 mi. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.
What is the formula to convert kilometers to miles?
Multiply the value in kilometers by 0.6213711922: miles = kilometers × 0.6213711922. For example, 5 km = 3.10686 mi.
How do I convert miles back to kilometers?
Multiply by the inverse factor 1.609344 (kilometers = miles × 1.609344), or use the miles-to-kilometers page.
Related conversions
Machine access
- API:
GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=km&to_unit=mi - MCP: server
https://tttkmbb.com/mcp, toolconvert_unitswith{"value":5,"from_unit":"km","to_unit":"mi"} - Markdown: https://tttkmbb.com/conversion/km-to-miles.md · JSON: https://tttkmbb.com/conversion/km-to-miles.json (add
?value=for a result) · Units: /api/v1/units?quantity=length - OpenAPI operationId:
convert_units. Freshness:static. Authentication: none.