Convert between km/h, mph, m/s, knots and ft/s.
Converted instantly in your browser.
How do you convert km/h to mph and other speed units?
Each speed is converted to metres per second, then to the target unit; for example, 1 mph = 0.44704 m/s and 1 knot = 0.514444 m/s. So 100 km/h = 62.137 mph = 27.778 m/s = 53.996 knots. A knot is one nautical mile per hour, used in aviation and at sea.
Understanding your result
A knot is one nautical mile per hour, used in aviation and at sea. km/h and mph are the common road-speed units.
Formula and method
Each speed is converted to metres per second, then to the target unit. For example, 1 mph = 0.44704 m/s and 1 knot = 0.514444 m/s.
Assumptions and limitations
Conversions are exact ratios based on standard definitions (1 mph = 0.44704 m/s, 1 knot = 1 nautical mile per hour). The tool converts an instantaneous speed value; it does not calculate average speed from distance and time, and it does not account for wind, current or measurement error in a real-world reading.
Worked example
100 km/h = 62.137 mph = 27.778 m/s = 53.996 knots.
Common speed conversions
| Convert | Equals |
|---|---|
| 1 km/h | 0.621371 mph |
| 1 mph | 1.60934 km/h |
| 1 m/s | 3.6 km/h |
| 1 m/s | 2.23694 mph |
| 1 knot | 1.852 km/h |
| 1 knot | 1.15078 mph |
| 100 km/h | 62.1371 mph |
| 60 mph | 96.5606 km/h |
| 1 mph | 1.46667 ft/s |
| 1 ft/s | 0.3048 m/s |
How to use this tool
- Enter the speed.
- Choose the units to convert from and to.
- Read the result and the full unit table.
Common mistakes to avoid
- Confusing kph and mph on speed limits — 100 km/h is only about 62 mph.
About the Speed Converter
Convert a speed between km/h, mph, m/s, knots and ft/s. Enter a value and read every unit at once.
Who should use this tool
Drivers and travellers converting speed limits between km/h and mph, runners and cyclists checking pace, pilots and sailors working in knots, and physics students moving between metres per second and other units. It covers m/s, km/h, mph, ft/s and knots.
Benefits
- Converts road, running, aviation and marine speeds in one place
- Uses exact factors, including the knot as one nautical mile per hour
- Instant and offline — useful abroad where limits are posted differently
- Shows several units at once so you can sanity-check a figure quickly
Practical use cases
- Converting a posted speed limit between km/h and mph when driving abroad
- Comparing running or cycling pace expressed in different units
- Reading aviation or sailing speeds given in knots
- Turning a physics answer in m/s into everyday km/h or mph
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Frequently asked questions
What is 100 km/h in mph?
100 km/h is about 62.14 mph.
What is a knot?
A knot is one nautical mile per hour, roughly 1.852 km/h.
How do I convert km/h to mph?
Multiply the km/h value by 0.621371 to get mph, so 100 km/h is about 62.1 mph. To convert mph to km/h, multiply by 1.60934 instead — 60 mph is about 96.6 km/h.
How fast is 1 metre per second?
One metre per second equals exactly 3.6 km/h, which is about 2.24 mph. It is a brisk walking-to-jogging pace, and multiplying any m/s value by 3.6 gives km/h directly.