Kilometers to nautical miles
1 kilometer = 0.539957 nautical miles
Type a value in kilometers (km) to get nautical miles (nmi) straight away. A kilometer is smaller than a nautical mile, so the number goes down. Both units belong to length, measured here against the meter.
1 km = 0.5399568 nmi
Formula
nmi = km × 0.5399568
One kilometer is 0.5399568 nautical miles, so multiply by that factor. You can also divide by 1.852, the number of kilometers in one nautical mile. Here km is the value in kilometers and nmi is the result in nautical miles.
Worked example: 42.195 kilometers × 0.5399568 = 22.7835 nautical miles.
Kilometers to nautical miles table
| kilometers (km) | nautical miles (nmi) |
|---|---|
| 1 km | 0.539957 nmi |
| 2 km | 1.07991 nmi |
| 3 km | 1.61987 nmi |
| 4 km | 2.15983 nmi |
| 5 km | 2.69978 nmi |
| 6 km | 3.23974 nmi |
| 7 km | 3.7797 nmi |
| 8 km | 4.31965 nmi |
| 9 km | 4.85961 nmi |
| 10 km | 5.39957 nmi |
| 15 km | 8.09935 nmi |
| 20 km | 10.7991 nmi |
| 25 km | 13.4989 nmi |
| 30 km | 16.1987 nmi |
| 40 km | 21.5983 nmi |
| 50 km | 26.9978 nmi |
| 60 km | 32.3974 nmi |
| 75 km | 40.4968 nmi |
| 100 km | 53.9957 nmi |
Everyday kilometers in nautical miles
| What it is | km | nmi |
|---|---|---|
| a 10–12 minute walk | 1 km | 0.539957 nmi |
| a 5K run | 5 km | 2.69978 nmi |
| a 10K run | 10 km | 5.39957 nmi |
| a half marathon | 21.0975 km | 11.3917 nmi |
| a marathon | 42.195 km | 22.7835 nmi |
Quick estimate in your head
Multiply by about 0.54. For 42.195 km that gives 22.79 nmi against an exact 22.7835 nmi, an error under 0.1%.
Watch out for
- A nautical mile (1,852 m) is about 15% longer than a statute mile (1,609 m).
About the units
Kilometer (km). 1,000 meters. Used for road distances and running races outside the US and UK.
Nautical mile (nmi). Exactly 1,852 m, about one minute of latitude. Used in sea and air navigation.
Going the other way, 1 nautical mile is 1.852 kilometers.
Questions
How many nautical miles are in 1 kilometer?
1 kilometer is 0.539957 nautical miles, and 1 nautical mile is 1.852 kilometers.
How do I convert kilometers to nautical miles?
Use nmi = km × 0.5399568. For example, 42.195 kilometers × 0.5399568 = 22.7835 nautical miles.
Is the kilometer to nautical mile factor exact?
The factor comes from the unit definitions. Results here are rounded to 6 significant digits for display.
How much is a marathon in nautical miles?
42.195 km is 22.7835 nmi.
Source for the conversion factor: NIST SP 811, Appendix B (conversion factors).
Related conversions
- nautical miles to kilometers
- kilometers to miles
- kilometers to meters
- nautical miles to miles
- miles to nautical miles
- centimeters to inches