Speed Converter
Convert between different speed units including mph, km/h, m/s, knots, and more.
Speed Conversion
Common Speeds
Speed Reference Guide
Common Speed Units
Meters per Second (m/s): SI base unit for speed
Kilometers per Hour (km/h): Common metric unit
Miles per Hour (mph): Imperial unit used in US/UK
Feet per Second (ft/s): Imperial unit for technical use
Knots: Nautical speed (1 knot = 1 nautical mile/hour)
Mach: Speed relative to sound (343 m/s at sea level)
Speed Comparisons
Human walking: ~5 km/h (3.1 mph)
Bicycle: ~20 km/h (12.4 mph)
Car (city): ~50 km/h (31 mph)
Car (highway): ~120 km/h (75 mph)
Commercial jet: ~900 km/h (560 mph)
Sound: 1,235 km/h (767 mph)
Understanding Speed Conversions
Speed conversions move between kilometers per hour (km/h), miles per hour (mph), meters per second (m/s) and knots. The SI unit is the meter per second, and every other unit is a rescaling of it over a fixed distance and time.
Useful anchors: 1 m/s is 3.6 km/h, and 1 mph is about 1.609 km/h. Knots (nautical miles per hour) are used in aviation and shipping, 1 knot is about 1.852 km/h. When converting a vehicle speed limit, remember the relationship is linear, so 100 km/h is roughly 62 mph.
Frequently Asked Questions
How do I convert km/h to mph?
Divide the km/h value by 1.60934, or multiply by 0.621371. For example, 100 km/h ≈ 62.1 mph.
How many km/h is 1 m/s?
One meter per second equals exactly 3.6 kilometers per hour.
What is a knot in mph?
One knot equals approximately 1.15078 mph (1.852 km/h).
How fast is 60 mph in km/h?
60 mph equals approximately 96.56 km/h.