Speed Converter
Speed is measured in different units depending on context. Kilometres per hour (km/h) is the metric standard for road speeds in most countries. Miles per hour (mph) is used in the United States and United Kingdom. Metres per second (m/s) is the SI unit of speed, used in scientific and engineering contexts. Knots (nautical miles per hour) are used in maritime navigation and aviation worldwide.
Key equivalences: one knot equals exactly 1.852 km/h by international definition. The speed of sound in dry air at 20°C is approximately 343 m/s (1,235 km/h or 767 mph).
Also try: Length Converter · Weight Converter · Temperature Converter · Volume Converter · Area Converter · Data Storage Converter · Cooking Converter
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. A useful rule of thumb: 60 mph ≈ 96.6 km/h, and 100 km/h ≈ 62.1 mph.
What is a knot in speed?
A knot is one nautical mile per hour. One knot equals exactly 1.852 km/h or approximately 1.151 mph. Knots are the international standard unit of speed for maritime navigation and aviation.
How do you convert m/s to km/h?
To convert metres per second to kilometres per hour, multiply by 3.6. For example, 10 m/s = 36 km/h. To convert km/h to m/s, divide by 3.6. This conversion is exact: 1 km/h = 1,000/3,600 m/s.
What is the speed of sound in km/h?
The speed of sound in dry air at 20°C is approximately 343 m/s, or about 1,235 km/h (767 mph). It varies with temperature and medium — sound travels faster in warmer air and faster still through water and solid materials.