Speed Converter - km/h, mph, m/s, knots

  • Kilometers per hour (km/h)
  • Miles per hour (mph)
  • Meters per second (m/s)
  • Knots (kn)
  • Feet per second (ft/s)
  • Miles per hour (mph)
  • Kilometers per hour (km/h)
  • Meters per second (m/s)
  • Knots (kn)
  • Feet per second (ft/s)
Results
—
—

Convert speed between the units used worldwide: km/h, mph, meters per second, knots, and feet per second. Our Speed Converter updates live as you type, with the conversion engine based on exact definitions (1 inch = 2.54 cm, 1 nautical mile = 1.852 km).

Common use cases: driving abroad (km/h speed limits vs mph odometers), running and cycling training (pace vs speed), aviation and marine navigation (knots), and physics homework (m/s).

Quick anchors: 100 km/h ≈ 62 mph; 60 mph ≈ 96.6 km/h; 1 m/s ≈ 2.24 mph; 1 knot ≈ 1.15 mph. Keep these in mind for fast mental conversions, and use the tool for precise values.

Formula
Convert to m/s (base unit), then to target unit. 1 m/s = 3.6 km/h ≈ 2.23694 mph, 1 knot = 1.852 km/h

FAQ

How do you convert km/h to mph?
Multiply km/h by 0.621371 to get mph. For example, 100 km/h ≈ 62.14 mph. To go the other way, multiply mph by 1.609344.
What is a knot?
A knot is one nautical mile (1.852 km) per hour. It is the standard speed unit in aviation and maritime navigation, and 1 knot ≈ 1.15078 mph.
How fast is m/s compared to km/h?
1 m/s equals exactly 3.6 km/h (multiply by 3.6). Physicists and engineers use m/s, while road signs use km/h or mph.
How fast is 100 km/h in mph?
100 km/h equals about 62.14 mph — a common highway speed limit conversion between metric and US units.

Related Calculators