Speed Converter
Convert between speed units
Common Conversions:
• 1 km/h ≈ 0.621 mph
• 1 m/s = 3.6 km/h
• 1 knot ≈ 1.852 km/h
• 100 km/h ≈ 62.1 mph
Frequently Asked Questions
How do I convert km/h to mph?
Multiply km/h by 0.621371. Example: 100 km/h = 100 × 0.621371 = 62.14 mph. Or divide by 1.60934.
What is the difference between knots and mph?
Knots measure nautical miles per hour (used in aviation and marine). 1 knot = 1.15078 mph = 1.852 km/h.
How fast is the speed of sound?
At sea level: ~343 m/s = ~1235 km/h = ~767 mph = ~661 knots. Varies with temperature and altitude.