Knots to MPH Speed Converter
Convert between knots, miles per hour, kilometers per hour, and meters per second. Knots are the standard speed unit in maritime navigation, aviation, and meteorology, defined as one nautical mile per hour.
A knot is one nautical mile per hour. The international nautical mile is defined as exactly 1,852 meters, making the knot a precisely defined unit. This converter uses that exact definition for all calculations.
Exact conversion factors:
- 1 knot = 1.852 km/h (exact, from the nautical mile definition)
- 1 knot = 1.15078 mph (derived from 1852 ÷ 1609.344)
- 1 knot = 0.514444 m/s (derived from 1852 ÷ 3600)
- 1 mph = 0.868976 knots
Speed Reference Table:
| Knots | MPH | km/h | m/s | Context |
|---|---|---|---|---|
| 5 | 5.75 | 9.26 | 2.57 | Light breeze sailing |
| 15 | 17.26 | 27.78 | 7.72 | Moderate sailing speed |
| 30 | 34.52 | 55.56 | 15.43 | Fast motorboat |
| 64 | 73.65 | 118.53 | 32.92 | Hurricane threshold |
| 250 | 287.69 | 463.00 | 128.61 | Commercial aircraft approach |
| 480 | 552.37 | 889.00 | 247.00 | Cruising airliner |
The term "knot" comes from the historical practice of measuring ship speed by counting knots on a rope as they passed over the stern. The knots were spaced at regular intervals, and a sandglass timed the measurement.