📏 Length Converter

Miles to Nautical Miles
( mi → nmi )

Instantly convert statute miles to nautical miles. Enter any value below and get an accurate result with the full formula and reference table.

Converter Tool
mi
nmi
Result
1 mile = 0.868976 nautical miles
0.868976
nmi
The Formula
nmi = mi × 0.868976
1 mile ≈ 0.868976 nautical miles (exactly 1609.344/1852).

How to Convert Miles to Nautical Miles

To convert statute miles to nautical miles, multiply the number of miles by 0.868976. This factor comes from the definitions: one statute mile equals 1,609.344 meters, while one nautical mile equals 1,852 meters. Therefore, 1 mi = 1609.344 / 1852 = 0.8689762419… nmi.

Step-by-Step Example

Let’s convert 10 miles to nautical miles:

1. Multiply by 0.868976: 10 × 0.868976 = 8.68976 nautical miles
2. So 10 miles is approximately 8.69 nautical miles.

For a distance of 100 miles: 100 × 0.868976 = 86.8976 nautical miles.

Why This Conversion?

The statute mile originated from Roman paces and was later standardized. The nautical mile is based on the Earth’s circumference — one minute of latitude. Since they are based on different references, the conversion factor is not a round number but is exact when using the meter definitions.

When You’d Use Each Unit

Statute miles are used on land in the US and UK for road distances and speed limits. 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.

Conversion Table

Common miles values converted to nautical miles — popular distances highlighted.

Miles (mi) Nautical Miles (nmi) Approximate
Frequently Asked Questions
How many nautical miles in a mile? +
One statute mile is approximately 0.868976 nautical miles. More precisely, 1 mi = 1609.344/1852 = 0.8689762419 nmi.
How do I convert 5 miles to nautical miles? +
5 × 0.868976 = 4.34488 nautical miles.
What is 20 miles in nautical miles? +
20 × 0.868976 = 17.37952 nmi.
How many miles in a nautical mile? +
One nautical mile is approximately 1.15078 miles.
What is 12 nautical miles in miles? +
12 × 1.15078 = 13.80936 miles (territorial waters limit).
Can I convert nautical miles back to miles with this tool? +
Yes! Just type a value into the nautical miles field and the miles field updates automatically. Or use the ⇄ swap button to switch directions.
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