Speed Converter
Convert speeds between km/h, m/s, miles per hour (mph) and knots: enter a value in one unit and read it off in the other three.
Note: These calculations are for informational purposes only and do not replace professional tax or financial advice. All information without guarantee.
FAQ
Frequently Asked Questions
How do I convert km/h to m/s?
Divide km/h by 3.6 to get m/s, or multiply m/s by 3.6 to get km/h. For example, 100 km/h equals about 27.78 m/s.
What are common speed units?
km/h is used in most countries, mph in the UK and US, knots for nautical and aviation, Mach for supersonic speeds (1 Mach is approximately 1,235 km/h at sea level).
How do I convert mph to km/h?
Multiply the value by 1.609344, because a mile is exactly 1,609.344 meters; the converter uses this exact factor (1 mph = 0.44704 m/s). Examples: the 70 mph speed limit on British motorways equals 112.65 km/h, and 55 mph equals 88.51 km/h. The other way round, 130 km/h is about 80.78 mph.
Guide
What is the Speed Converter?
The speed converter converts between km/h, m/s, mph, knots and other speed units.
How does the Speed Converter work?
Enter the value and source unit. The calculator converts to all common speed units.
Key Data and Facts
1 km/h = 0.2778 m/s. 1 mph = 1.609 km/h. 1 knot = 1.852 km/h. Speed of sound: approx. 1,235 km/h (Mach 1).
Step-by-Step Guide
How to use the speed converter step by step: 1. Choose the source unit – km/h, m/s, mph (miles per hour), knots (kn) or Mach. 2. Enter the value – the converter immediately converts it into all units. 3. Important conversions: km/h to m/s = value / 3.6. mph to km/h = value * 1.609. Knots to km/h = value * 1.852. 4. Mach number: Mach 1 = the speed of sound = approx. 1,235 km/h (at sea level at 20 degrees C). At flight altitude (approx. -57 degrees C) Mach 1 is only approx. 1,062 km/h. 5. Common applications: converting speed limits abroad (65 mph = 104.6 km/h), converting wind speeds from knots to km/h (Beaufort 8 = approx. 34-40 kn = 63-74 km/h), calculating running speeds. Tip: for a quick km/h-to-mph estimate, divide the value by 1.6 (100 km/h ≈ 62 mph).
Calculation Example
130 km/h in mph: 130 / 1.609 = 80.8 mph. 25 knots in km/h: 25 * 1.852 = 46.3 km/h.
Sources
Official sources
Calculations are based on applicable German laws and official data:
Full methodology at Methodology.
Reviewed by Konstantin Iakovlev · Last updated:
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