Nautical Miles to Kilometers Converter (nmi to km)
1 nmi = 1.852 km exactly. Convert nautical miles to kilometers for maritime zones, sailing races, flight plans and chart distances.
Kilometer (km) = Nautical Mile (nmi) × 1.852
Nautical Mile (nmi): The international nautical mile is exactly 1852 metres. It was chosen because it is close to one minute of latitude, and it is used in sea and air navigation together with the knot (one nautical mile per hour).
Kilometer (km): The kilometre is 1,000 metres. One international mile is exactly 1.609344 km; to convert kilometres to miles, divide by 1.609344.
| Nautical Mile (nmi) | Kilometer (km) |
|---|---|
| 1 | 1.852 |
| 5 | 9.26 |
| 10 | 18.52 |
| 25 | 46.3 |
| 50 | 92.6 |
| 100 | 185.2 |
Charts, maritime law and flight plans measure distance in nautical miles, while maps and road signs in most countries use kilometers. The international nautical mile was fixed at exactly 1,852 m in 1929, so 1 nmi = 1.852 km and the conversion involves no rounding.
The unit was chosen because one nautical mile is close to one minute of latitude, which lets a navigator measure distance straight off the latitude scale of a chart. The kilometer has a similar origin, as one ten-thousandth of the distance from the pole to the equator, so 90 degrees of latitude is about 5,400 nautical miles and about 10,000 km.
How to use this tool
- Type a value in the Nautical Mile box to see it in kilometers, or type in the Kilometer box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Length converter.
Formula
Kilometer (km) = Nautical Mile (nmi) × 1.852
Nautical Mile (nmi) = Kilometer (km) × 0.539956803456
Both factors come from exact definitions: 1 kilometer = 0.539956803456 nautical miles and 1 nautical mile = 1.852 kilometers (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
12 nmi × 1.852 = 22.224 km
100 km × 0.539956803456 ≈ 53.9957 nmi
Nautical Mile to Kilometer chart
Common values from nautical miles to kilometers, rounded to four decimal places.
| Nautical Mile (nmi) | Kilometer (km) |
|---|---|
| 0.1 | 0.1852 |
| 0.5 | 0.926 |
| 1 | 1.852 |
| 2 | 3.704 |
| 3 | 5.556 |
| 5 | 9.26 |
| 10 | 18.52 |
| 12 | 22.224 |
| 15 | 27.78 |
| 20 | 37.04 |
| 24 | 44.448 |
| 25 | 46.3 |
| 50 | 92.6 |
| 60 | 111.12 |
| 100 | 185.2 |
| 150 | 277.8 |
| 200 | 370.4 |
| 250 | 463 |
| 300 | 555.6 |
| 500 | 926 |
| 1,000 | 1,852 |
| 2,000 | 3,704 |
| 3,000 | 5,556 |
Kilometer to Nautical Mile chart
The reverse direction for values people often look up.
| Kilometer (km) | Nautical Mile (nmi) |
|---|---|
| 1 | 0.54 |
| 5 | 2.6998 |
| 10 | 5.3996 |
| 20 | 10.7991 |
| 22 | 11.879 |
| 37 | 19.9784 |
| 44 | 23.7581 |
| 50 | 26.9978 |
| 185 | 99.892 |
| 370 | 199.784 |
| 500 | 269.9784 |
| 1,000 | 539.9568 |
| 5,000 | 2,699.78 |
Distances defined in nautical miles
| Zone or route | Nautical Mile (nmi) | Kilometer (km) |
|---|---|---|
| Territorial sea, maximum breadth (UNCLOS) | 12 | 22.224 |
| Contiguous zone, maximum breadth | 24 | 44.448 |
| Exclusive economic zone, maximum breadth | 200 | 370.4 |
| Sydney to Hobart Yacht Race | 628 | 1,163.06 |
| One degree of latitude, approximately | 60 | 111.12 |
| One minute of latitude, approximately | 1 | 1.852 |
Quick mental estimate
Double the nautical miles and take away 15% of the original figure: 12 nmi → 24 − 1.8 = 22.2 km, against an exact 22.224 km. The method multiplies by 1.85, about 0.1% under the true factor of 1.852.
Use the converter or the charts when the exact figure matters.
The two units
Nautical Mile (nmi): The international nautical mile is exactly 1852 metres. It was chosen because it is close to one minute of latitude, and it is used in sea and air navigation together with the knot (one nautical mile per hour).
Kilometer (km): The kilometre is 1,000 metres. One international mile is exactly 1.609344 km; to convert kilometres to miles, divide by 1.609344.
Frequently asked questions
How far is 12 nautical miles in kilometers?
Exactly 22.224 km. Twelve nautical miles is the maximum breadth of the territorial sea under the UN Convention on the Law of the Sea, measured from the coastal baseline.
How far offshore does the 200-mile zone reach?
The exclusive economic zone extends up to 200 nmi from the baselines, which is 370.4 km. News reports sometimes call it a 200-mile zone, but the miles are nautical, not statute; in statute miles it is about 230.
Why is a nautical mile longer than a kilometer?
Its length comes from the size of the Earth, not from the metric system: a minute of latitude averages close to 1,852 m. A kilometer is 1,000 m, so a nautical mile is 1.852 times as long.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/nautical-mile-to-kilometer-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). Nautical Miles to Kilometers Converter (nmi to km). https://kakao.mobile/tools/nautical-mile-to-kilometer-converter/
“Nautical Miles to Kilometers Converter (nmi to km).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/nautical-mile-to-kilometer-converter/.
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