How do I convert km/h to mph?
Multiply kilometers per hour by 0.621371. For example, 100 km/h is about 62.1371 mph.
Speed Converter
Convert speed between km/h, mph, meters per second, and knots. Get accurate results plus common formulas for road, wind, marine, and aviation speeds.
Last updated: September 2026
8 significant digits
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1 m/s = 3.6 km/h
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Common speed units
Convert speed units like m/s, km/h, mph, and knots. Use OmniUnit for fast conversions between common units without leaving the page.
- Meters per second (m/s)
- Kilometers per hour (km/h)
- Miles per hour (mph)
- Knot (kn)
How to use this speed converter
Convert between kilometers per hour, miles per hour, meters per second, and knots. OmniUnit uses exact stored factors and rounds only the displayed result.
What to check
- Road speeds are commonly shown in km/h or mph.
- Knots are standard in marine navigation and widely used in aviation.
- Meters per second are common in physics, engineering, and weather data.
Quick answers
How do I convert mph to km/h?
Multiply miles per hour by 1.609344. For example, 60 mph is about 96.5606 km/h.
How fast is one knot in km/h?
One knot equals exactly 1.852 kilometers per hour.
What is the difference between knots and mph?
A knot is one nautical mile per hour. One knot is about 1.15078 mph.