Kilometers to Nautical Miles
( km → nmi )
Instantly convert kilometers to nautical miles. Enter any value below and get an accurate result with the full formula and reference table.
How to Convert Kilometers to Nautical Miles
To convert kilometers to nautical miles, multiply the number of kilometers by 0.539957. This factor comes from the definition: one nautical mile equals 1.852 kilometers, so 1 km = 1/1.852 nmi ≈ 0.539957 nmi.
Step-by-Step Example
Let’s convert 10 kilometers to nautical miles:
1. Multiply by 0.539957: 10 × 0.539957 = 5.39957 nmi
2. So 10 kilometers is approximately 5.4 nautical miles.
For a distance of 100 km: 100 × 0.539957 = 53.9957 nmi.
Why 0.539957?
The nautical mile was historically defined as one minute of latitude. In 1929, the international nautical mile was standardized to exactly 1,852 meters. Therefore, 1 km = 1000 / 1852 = 0.539956803… nmi. The value 0.539957 is a convenient rounded figure for everyday use, but the converter uses the precise factor to ensure accuracy.
When You’d Use Each Unit
Kilometers are the standard unit of distance on land in most countries. Nautical miles are used in aviation, marine navigation, and for international boundaries at sea. Converting between them is essential for flight planning, sea travel, and understanding global distances.
Common kilometers values converted to nautical miles — popular distances highlighted.
| Kilometers (km) | Nautical Miles (nmi) | Approximate |
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