Miles to Nautical Miles
Type a value in either box to convert between miles and nautical miles. The factor is 0.868976.
| Miles | Nautical Miles |
|---|---|
| 1 mi | 0.868976 nmi |
| 2 mi | 1.737952 nmi |
| 3 mi | 2.606929 nmi |
| 5 mi | 4.344881 nmi |
| 10 mi | 8.689762 nmi |
| 25 mi | 21.724406 nmi |
| 50 mi | 43.448812 nmi |
| 100 mi | 86.897624 nmi |
How to use
- Enter a value in the Miles field.
- The Nautical Miles figure appears immediately — no button to press.
- Typing in the Nautical Miles field converts back to Miles the same way.
- Use the reference table for the values that come up most often.
Miles to Nautical Miles formula
To convert miles to nautical miles, multiply by 0.868976242.
nmi = mi × 0.868976242
Why this factor: the mile and the nautical mile are both defined against the meter, so dividing one definition by the other gives 0.868976242 directly. Both definitions are set out in full below.
To go the other way, divide by 0.868976242 — or use the Nautical Miles to Miles converter, which is the same calculation reversed.
Worked example
Take 100 mi and multiply by the factor 0.868976242: the result is 86.897624 nmi.
100 mi × 0.868976242 = 86.897624 nmi
The converter above does this for any value you type, in either direction.
What is a mile?
The statute mile is the standard long-distance unit in the United States and the United Kingdom.
Definition: Defined as 5,280 feet, which since the 1959 International Yard and Pound Agreement makes it exactly 1,609.344 meters.
Where it is used: US and UK road signs, speed limits, running races, and vehicle odometers.
Worth knowing: Distinct from the nautical mile (1,852 m), which is about 15% longer and used at sea and in the air.
What is a nautical mile?
A nautical mile is the distance unit of sea and air navigation, chosen so it tracks latitude on a chart.
Definition: Exactly 1,852 meters, fixed by the 1929 International Extraordinary Hydrographic Conference. It approximates one arcminute of latitude.
Where it is used: Marine and aviation navigation, maritime boundaries, and the basis of the knot (one nautical mile per hour).
Worth knowing: About 15% longer than a statute mile — mixing the two is a classic navigation error.
Miles vs Nautical Miles
The mile is an imperial unit while the nautical mile is a specialized unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many nautical miles are in a mile?
One mile equals 0.868976242 nautical miles.
What is the formula to convert miles to nautical miles?
Multiply the number of miles by 0.868976242. To reverse it, divide by 0.868976242 instead.
How do I convert nautical miles back to miles?
Divide by 0.868976242, which is the same as multiplying by 1.15077945.
How many nautical miles are in 10 miles?
10 mi works out to 8.689762 nmi.
Is there anything to watch out for with miles?
Distinct from the nautical mile (1,852 m), which is about 15% longer and used at sea and in the air.
How is the mile defined?
Defined as 5,280 feet, which since the 1959 International Yard and Pound Agreement makes it exactly 1,609.344 meters.