Speed Converter
Convert between mph, km/h, m/s, knots, and Mach with instant live results.
Speed Conversion
Metric
Imperial & Special
Real-World Speed Examples
🏃 Bonus: Running Pace Converter
Convert between speed (km/h, mph) and running pace (min/km, min/mile)
Tip: Type in any speed unit and all others update instantly. Use copy buttons (📋) to copy values.
How it works
Base Unit: 1 meter per second (m/s) Speed Conversions to m/s: 1 km/h = 0.27778 m/s | 1 mph = 0.44704 m/s | 1 knot = 0.51444 m/s 1 ft/s = 0.3048 m/s | 1 Mach = 343 m/s (at sea level) Real-World Speeds: Speed of sound = 343 m/s = 1235 km/h = Mach 1 Usain Bolt (100m record) = 44.72 km/h = 27.79 mph SA highway limit = 120 km/h = 74.6 mph US highway limit = 75 mph = 120.7 km/h Cruising aircraft = 900 km/h = 560 mph = Mach 0.85 Bullet train = 320 km/h = 199 mph Bonus: Running Pace Converter Convert speed (km/h, mph) to running pace (min/km, min/mile) and vice versa
Enter a speed in any unit and see the conversion to all others instantly. Supports metric (km/h, m/s), imperial (mph, ft/s), nautical (knots), and Mach numbers. Includes real-world speeds: Usain Bolt's record, highway limits, aircraft cruising speed, bullet trains, and the sound barrier. Bonus: Convert between speed and running pace (minutes per kilometre or mile).
Why this matters
Speed is measured differently around the world. Most countries use km/h; the US uses mph; sailors and pilots use knots and Mach. When you're driving across borders, flying internationally, running a race, or reading speed specifications, you need to convert. A 120 km/h highway might feel different than 75 mph—but they're identical. This calculator makes those conversions instant, and the bonus pace converter helps runners understand their speed versus their running pace.
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Learn more
The complete guide to speed converter
Formulas, examples, and tips explained in plain English