Convert Miles to Nautical miles
1 mile is 0.87 nmi. One mile is exactly 0.868976241901 nautical miles.
One mile is 0.86897624 nautical miles. To convert miles to nautical miles, multiply by 0.86897624; to go the other way, divide by 0.86897624 or multiply by 1.1507794. The relation is exact but the figure is not: it is a rounding of a number that does not terminate, and it follows from NIST. Exactly 5,280 feet — a survivor of the Roman mille passus, rounded up by an English statute of 1593.
Factor checked against the defining standard · How we check
- Miles × 0.86897624
1 * 0.86897620.869 nmi
1 mile in every length unit
| Unit | Value | Exact factor |
|---|---|---|
| inches | 63,360 in | × 63,360 |
| feet | 5,280 ft | × 5,280 |
| yards | 1,760 yd | × 1,760 |
| miles (as entered) | 1 mi | — |
| millimeters | 1,609,344 mm | × 1,609,344 |
| decimetres | 16,093.44 dm | × 16,093.44 |
| centimeters | 160,934.4 cm | × 160,934.4 |
| meters | 1,609.344 m | × 1,609.344 |
| kilometers | 1.609344 km | × 1.609344 |
| nautical miles | 0.8689762419 nmi | × 0.868976241901 |
| micrometers | 1,609,344,000 µm | × 1,609,344,000 |
| nanometers | 1,609,344,000,000 nm | × 1,609,344,000,000 |
| thou | 63,360,000 thou | × 63,360,000 |
Factors are entered by hand from NIST rather than derived from a units library, so the ones that terminate are exact rather than rounded.
How do you convert miles to nautical miles? The converter and the working
- 1.Take the measurement in miles.
- 2.Multiply by 0.86897624 — that is how many nautical miles fit in one mile.
- 3.To go back the other way, divide by 0.86897624, or multiply by 1.1507794.
Worked example: 25 miles to nautical miles
- Formula
- mi × 0.86897624 = nmi
- Arithmetic
- 25 × 0.86897624 = 21.72 nmi
- Answer
- 25 mi = 21.72 nmi
The factor is rounded for display; the figure above is computed from the full value.
Miles to nautical miles conversion table
| Miles | Nautical miles |
|---|---|
| 1 mi | 0.87 nmi |
| 2 mi | 1.74 nmi |
| 3 mi | 2.61 nmi |
| 4 mi | 3.48 nmi |
| 5 mi | 4.34 nmi |
| 6 mi | 5.21 nmi |
| 7 mi | 6.08 nmi |
| 8 mi | 6.95 nmi |
| 9 mi | 7.82 nmi |
| 10 mi | 8.69 nmi |
| 12 mi | 10.43 nmi |
| 15 mi | 13.03 nmi |
| 20 mi | 17.38 nmi |
| 25 mi | 21.72 nmi |
| 50 mi | 43.45 nmi |
| 100 mi | 86.9 nmi |
| 200 mi | 173.8 nmi |
| 300 mi | 260.69 nmi |
| 500 mi | 434.49 nmi |
| 1000 mi | 868.98 nmi |
| 2000 mi | 1,737.95 nmi |
| 5000 mi | 4,344.88 nmi |
| 10000 mi | 8,689.76 nmi |
A nautical mile is a minute of latitude, which is why it is not a mile
It is exactly 1,852 meters — about 1.151 statute miles — and it was chosen so that one minute of latitude equals one nautical mile anywhere on a chart. That is also why speed at sea is measured in knots: one knot is one nautical mile an hour, so a position, a distance and a speed all use the same units without conversion.
NIST Special Publication 811 — Guide for the Use of the International System of Units
What is a mile?
Exactly 5,280 feet — a survivor of the Roman mille passus, rounded up by an English statute of 1593.
What is a nautical mile?
Exactly 1,852 meters by international agreement since 1929, chosen because it is one minute of latitude — which is why a chart, a speed in knots and a position in degrees all use the same arithmetic.
How many nautical miles are in a mile?
One mile is 0.86897624 nautical miles. Going the other way, one nautical mile is 1.1507794 miles. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.
Every length unit here
The whole group — 13 units with their symbols and the size of each one in meters — is on the conversion index, along with every pair it makes. The table above already gives each of them relative to a mile.
Source: NIST — international yard and pound agreement (inch = 25.4 mm exactly)
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Questions people actually ask
- How many nautical miles are in a mile?
- 0.86897624. Exactly 1,852 meters by international agreement since 1929, chosen because it is one minute of latitude — which is why a chart, a speed in knots and a position in degrees all use the same arithmetic.
- How do I convert nautical miles back to miles?
- Divide by 0.86897624, or multiply by 1.1507794 — they are the same operation.
Other length conversions
Nautical miles to miles — the same conversion the other way.