How Do You Convert km/h to mph?
Explore Kilometer per Hour
Convert meters per second, kilometers per hour, miles per hour, knots, and more. Our speed converter is useful for driving, aviation, weather reports, and sports performance tracking.
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How it works
Speed conversion between metric and imperial is straightforward: multiply km/h by 0.621371 to get mph. Knots (used in aviation and maritime navigation) equal exactly 1.852 km/h. m/s × 3.6 = km/h.
Quick reference
Frequently Asked Questions
How many km/h is 1 mph?
1 mile per hour equals 1.60934 km/h. To convert mph to km/h, multiply by 1.60934.
What is the speed of sound in km/h?
The speed of sound in air at sea level is approximately 1,235 km/h (343 m/s or 767 mph).
What is a knot in km/h?
1 knot equals 1.852 km/h. Knots are the standard unit of speed in maritime and aviation contexts.
How fast is 100 km/h in mph?
100 km/h equals approximately 62.14 mph. This is a common highway speed limit in many countries.
How do you convert m/s to km/h?
Multiply the m/s value by 3.6. For example, 10 m/s × 3.6 = 36 km/h.
How fast does a commercial airplane fly?
Commercial aircraft cruise at 800–920 km/h (500–570 mph), which is roughly Mach 0.75–0.85. A Boeing 737 typically cruises at about 840 km/h (520 mph). The Concorde flew at Mach 2, or about 2,180 km/h (1,354 mph), but was retired in 2003.
How fast is the fastest human?
Usain Bolt set the 100 m world record of 9.58 seconds in 2009, reaching a peak speed of approximately 44.72 km/h (27.8 mph or 12.4 m/s) between the 60 m and 80 m marks. The average speed over the full 100 m was about 37.6 km/h (23.4 mph).
What is the speed of sound?
The speed of sound in air at 20°C (68°F) is approximately 343 m/s, or 1,235 km/h (767 mph). This is known as Mach 1. The speed varies with temperature: at 0°C it is 331 m/s, and at 30°C it is 349 m/s. In water, sound travels about 4.3× faster at roughly 1,480 m/s.
What are typical highway speed limits around the world?
Highway speed limits vary by country: Germany Autobahn has an advisory speed of 130 km/h (81 mph) with no general limit on some sections; France, Spain, and Italy use 130 km/h; the UK is 70 mph (113 km/h); the US interstate limits range from 65–80 mph (105–129 km/h); Australia uses 100–110 km/h (62–68 mph).
How fast does a bicycle go?
A casual cyclist on flat ground averages 15–20 km/h (9–12 mph). A fit recreational rider maintains 25–30 km/h (15–19 mph). Professional road cyclists average 40–45 km/h (25–28 mph) during races. The cycling land speed record is 296 km/h (184 mph), set in a streamlined recumbent bike in 2018.