Nautical Miles to Kilometers Converter
Instantly convert nautical miles (NM) to kilometers (km). A nautical mile is exactly 1,852 meters by international agreement, so the conversion is precise—no approximation needed.
1. Core Idea
1 nautical mile (NM) = 1.852 kilometers (km) exactly. Multiply nautical miles by 1.852 to get kilometers.
2. Conversion Formula
kilometers = nautical miles × 1.852
The factor comes from the definition: one nautical mile corresponds to one minute of latitude and is standardized at 1,852 meters.
3. Quick Values
4. 3-Step Example
Convert 7.5 nautical miles to kilometers
- Write the formula: km = NM × 1.852
- Insert the value: km = 7.5 × 1.852
- Calculate: 7.5 × 1.852 = 13.89 km
Answer: 7.5 NM = 13.89 km
5. Common Uses
- Marine navigation: Distances on nautical charts.
- Aviation: Flight planning and air traffic separation.
- Weather & ocean data: Storm track distances.
- Maritime law: Territorial sea limits (e.g., 12 NM).
6. Accuracy & Tips
- The 1.852 factor is exact—no rounding uncertainty.
- Mental shortcut: Double NM and subtract about 8% (≈ NM × (2 − 0.148)).
- For knots (speed in NM/hour), multiply by 1.852 to get km/h.
- Large voyage distances often rounded to the nearest whole NM before conversion.
7. More Examples
| Nautical Miles (NM) | Kilometers (km) |
|---|---|
| 0.25 | 0.463 km |
| 0.5 | 0.926 km |
| 1 | 1.852 km |
| 4 | 7.408 km |
| 8 | 14.816 km |
| 12 | 22.224 km |
| 25 | 46.30 km |
| 40 | 74.08 km |
| 75 | 138.9 km |
| 120 | 222.24 km |
8. FAQ
What is a nautical mile?
A unit based on the Earth's geometry: one minute of latitude, defined exactly as 1,852 meters.
How is it different from a regular (statute) mile?
1 statute mile = 1.60934 km, while 1 nautical mile = 1.852 km—about 15% longer.
How do I convert speed in knots to km/h?
Multiply knots by 1.852. Example: 12 knots = 22.224 km/h.
Mental estimate trick?
NM × 2 then subtract roughly 7–8%. Example: 18 NM → 36 − 2.8 ≈ 33.2 km (exact: 33.336 km).