Knots to MPH Converter

Convert knots to miles per hour and back instantly.

Knots to MPH Quick Reference

Knots (kn) Miles per hour (mph) Kilometers per hour (km/h)
11.15081.852
55.75399.26
1011.507818.52
2023.015637.04
5057.539092.6
100115.0779185.2

What Is a Knot?

A knot is a unit of speed equal to one nautical mile per hour. Since a nautical mile is defined as 1,852 meters, one knot equals exactly 1.852 kilometers per hour. The term originates from the historical practice of measuring a ship's speed by paying out a knotted rope, the "common log," over a fixed period of time and counting the knots that passed. Today the knot is the standard unit of speed in maritime and aviation contexts worldwide.

The Conversion Factor

Because one nautical mile (1,852 m) is longer than one statute mile (1,609.344 m), a speed expressed in knots is numerically larger when converted to miles per hour. The exact conversion factor is:

  • 1 knot = 1.15077945 mph (multiply knots by 1.15077945)
  • 1 mph = 0.86897624 knots (divide mph by 1.15077945)
  • 1 knot = 1.852 km/h (exact, by definition)

Where Knots Are Used

Aviation

Pilots report airspeed and ground speed in knots, which simplifies navigation because one minute of latitude equals one nautical mile.

Maritime

Ships and boats measure speed in knots. Converting to mph helps recreational boaters relate vessel speed to familiar road speeds.

Weather

Wind speed in marine and aviation forecasts is reported in knots, including hurricane and storm intensity classifications.