Nautical miles and miles
The international nautical mile is exactly 1,852 meters, close to one minute of latitude. Sea and air navigation measure distance in nautical miles and speed in knots (nautical miles per hour).
The international mile is exactly 1,760 yards, or 1,609.344 meters, under the 1959 yard and pound agreement. Road distances and speed limits in the United States and United Kingdom use miles.
Worked example
Convert 100 nmi: 100 × 1.150779448 = 115.0779448, so 100 nautical miles is 115.0779448 miles. Likewise 200 nmi = 230.1558896 mi.
Estimating in your head
Multiply by 1.2 for a quick figure; it is off by about 4.3%. For 100 nmi that gives 120 mi, against 115.078 exactly.
Going the other way
To convert miles to nautical miles, divide by 1.150779448 (or multiply by 0.868976241901).
How this works
mi = nmi × 1.150779448
1 nmi = 1,852 m and 1 mi = 1,609.344 m, both by definition, so the factor is their ratio: 1.150779448 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.
Frequently asked
How many miles are in a nautical mile?
1 nautical mile = 1.150779448 miles. The factor is exact by definition but has endless decimals, so it is shown rounded; the page uses the full value.
How do I convert nautical miles to miles?
Multiply by 1.150779448. For example, 200 nmi × 1.150779448 = 230.1558896 mi.
What is 1,000 nmi in miles?
1,000 nmi = 1,150.779448 mi. The table next to the converter lists more common values.
Is the result rounded?
Only on screen. The page computes with the exact definitions and removes floating-point noise past 15 significant digits; pick 3 to 12 significant figures, or use Copy result for the full value.
Sources
- NIST SP 811 Appendix B.8 — Factors for units listed alphabetically
- Federal Register 59-5442 (1959) — Refinement of values for the yard and the pound
- Wikipedia — Conversion of units of length
Reviewed Oct 17, 2026 · test vectors fixtures/units/length/nautical-miles-to-miles/