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Convert between km/h, mph, m/s, knots, and ft/s instantly.
🏃 Supports m/s, km/h, mph, knots, and ft/s. Common use: converting speed limits between countries.
Speed is measured differently depending on context and country. km/h and mph dominate everyday driving, m/s is standard in physics and engineering, knots are used in aviation and maritime, and ft/s appears in some US engineering contexts.
A knotis one nautical mile per hour, where a nautical mile is based on the Earth's circumference (one minute of latitude). Because nautical miles relate directly to navigation, knots remain the standard in aviation and maritime use worldwide, even in countries that use metric for everything else.
The Speed Converter converts speed converterfrom one unit to another using the exact internationally defined conversion factors. Type a value, choose your source and target units, and the converted result is shown instantly — no waiting, no page reload.
Manual conversion is error-prone because it means memorizing ratios (how many feet in a meter, how many pints in a liter). This tool removes that friction: the conversion factor is built in, and the math is done to full precision with no rounding until the final displayed number.
Common uses: people reach for this tool when they need to look up a mph to kmh converter, kmh to mph converter, knots to mph converter, or convert speed for driving abroad.
Browser-based tools like this one have a few real advantages over installed software or manual methods:
The Speed Converter is based on the following formula:
km/h = m/s × 3.6 mph = km/h ÷ 1.609344 1 knot = 1.852 km/h 1 ft/s = 0.3048 m/s
Variables: m/s = meters per second, the SI unit km/h = kilometers per hour mph = miles per hour (1 mi = 1609.344 m) knot = nautical miles per hour (1 nmi = 1852 m) ft/s = feet per second
The mile is exactly 1609.344 m, so 1 mph = 1.609344 km/h. The 3.6 factor between m/s and km/h comes from 3600 seconds per hour divided by 1000 meters per kilometer. Knots are nautical miles per hour and are standard at sea and in aviation.
Worked example: Convert 100 km/h: mph = 100 ÷ 1.609344 ≈ 62.14 mph m/s = 100 ÷ 3.6 ≈ 27.78 m/s Reverse: 60 mph × 1.609344 = 96.56 km/h
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