Knots to MPH Calculator — Knots to Miles per Hour
Convert any speed in knots (nautical miles per hour) to miles per hour (mph), kilometres per hour (km/h) and metres per second (m/s). 1 knot = 1.150779 mph because 1 nautical mile = 1852 m and 1 statute mile = 1609.344 m.
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1 knot = 1.150779 mph — based on 1 nmi = 1852 m and 1 mi = 1609.344 m
- 1
Nautical mile in metres
1 nmi = 1,852 m = 1,852 - 2
Statute mile in metres
1 mi = 1,609.344 m = 1,609.344 - 3
mph per knot
1,852 ÷ 1,609.344 = 1.150779Both definitions are exact since 1959. - 4
Convert to mph
20 × 1.150779 = 23.0156
How does this calculator work?
1 knot = 1.150779 mph = 1.852 km/h = 0.5144 m/s. The factor comes from dividing 1 nautical mile (1852 m) by 1 statute mile (1609.344 m). Multiply knots by 1.15 for a quick mph estimate, or by 1.852 for km/h. Knots are the standard in aviation and maritime navigation worldwide.
Formula
How this is calculated
A knot is defined as exactly one nautical mile per hour. The nautical mile is an international standard of exactly 1852 metres, chosen because it equals one arc-minute of latitude — a natural fit for navigation using latitude and longitude. The statute mile used in mph is exactly 1609.344 metres. Dividing the nautical mile by the statute mile gives the conversion factor: 1852 ÷ 1609.344 ≈ 1.150779 mph per knot.
The kilometre-per-hour conversion is even simpler: 1 knot = 1852 m/h = 1.852 km/h exactly, because 1 km = 1000 m. The metres-per-second result divides the 1852 m by 3600 seconds in an hour, giving 1 knot ≈ 0.5144 m/s.
Knots are the standard speed unit in both maritime and aviation navigation worldwide, mandated by ICAO (for aircraft) and IMO (for ships). Wind speeds on aviation and marine weather reports are also given in knots. At typical cruise speeds — a commercial airliner at 450 kn ≈ 518 mph ≈ 833 km/h — the distinction between knots and mph matters significantly, and conversions must be accurate.
Frequently asked questions
1 knot = 1852 / 1609.344 ≈ 1.150779 mph. For a quick estimate, multiply knots by 1.15 to get mph.
One nautical mile equals one arc-minute of latitude, so measuring distances and speeds in nautical miles and knots keeps navigation arithmetic consistent with latitude/longitude charts. International conventions (ICAO for aviation, IMO for shipping) standardised knots globally, so pilots and mariners share a universal speed language regardless of their country.
A nautical mile (nmi) is a distance unit equal to exactly 1852 metres — roughly the length of one arc-minute of latitude on Earth. A knot is a speed unit: one nautical mile per hour. You travel at 20 knots when you cover 20 nautical miles in one hour.
Also known as
TG we-Calculate Editorial Team. (2026). Knots to MPH Calculator — Knots to Miles per Hour [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/knots-to-mph-calculator
TG we-Calculate Editorial Team. "Knots to MPH Calculator — Knots to Miles per Hour." TG we-Calculate. 2026. https://we-calculate.com/calculator/knots-to-mph-calculator.
TG we-Calculate Editorial Team, "Knots to MPH Calculator — Knots to Miles per Hour," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/knots-to-mph-calculator
@misc{wecalculate_knots_to_mph_calculator, title = {Knots to MPH Calculator — Knots to Miles per Hour}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/knots-to-mph-calculator}}, year = {2026}, note = {TG we-Calculate} }
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