Speed Converter
Convert between mph, km/h, m/s, knots, and ft/s.
Last updated: September 23, 2026
Common speed conversions
| Speed | Equal to |
|---|---|
| 60 mph | 96.6 km/h |
| 100 km/h | 62.1 mph |
| 1 knot | 1.852 km/h (1.15 mph) |
| 1 m/s | 3.6 km/h (2.24 mph) |
What is a knot?
A knot is one nautical mile per hour, used in aviation and boating. It's based on the nautical mile (1,852 meters), which was originally defined as one minute of latitude, making it directly useful for navigation and charting.
Where these units show up in real life
Renting a car abroad is the most common reason people reach for mph-to-km/h conversion nearly every country except the US, UK, Liberia, and Myanmar posts speed limits in km/h, and a US speedometer that only shows mph makes it easy to misjudge a foreign highway's speed limit. Pilots and sailors think in knots because aviation charts, marine charts, and wind reports are built around nautical miles. Runners and cyclists more often think in pace (minutes per mile or per kilometer) than raw speed, but converting a race pace to mph or km/h is useful for comparing training data across apps that report speed differently. Scientists and engineers default to meters per second because it's the SI base unit for velocity.
How the conversion works
Every unit here is converted through meters per second as a common reference: 1 mph = 0.44704 m/s, 1 km/h = 0.277778 m/s, 1 knot = 0.514444 m/s, and 1 ft/s = 0.3048 m/s. Converting between any two units means converting the input to m/s first, then from m/s to the target unit.
FAQ
Why do some countries use km/h and others use mph?
Most countries adopted the metric system for road signage and use km/h, while the US, UK, and a handful of others (including Liberia and Myanmar) kept miles per hour. The UK is a partial exception it uses mph for road speeds but metric units almost everywhere else.
How fast is a 6-minute-mile running pace in mph?
A 6-minute mile works out to exactly 10 mph (about 16.1 km/h). Pace and speed are inverses of each other, so a faster pace (lower minutes per mile) always means a higher mph figure.
Why do pilots and sailors use knots instead of mph?
Nautical charts and GPS coordinates are both based on degrees of latitude and longitude, and a knot was defined so that 1 knot roughly equals 1 minute of latitude per hour making speed, distance, and navigation calculations line up without extra conversion.
Is a knot the same as a mile per hour?
No. A knot (1.852 km/h) is about 15% faster than a mile per hour (1.609 km/h) a common mix-up since both are called "miles per hour" colloquially, but a nautical mile is longer than a statute mile.
What speed is considered highway speed in most countries?
Highway speed limits commonly range from 100-130 km/h (62-81 mph) outside the US, compared to 65-80 mph (105-129 km/h) on most US interstates roughly comparable once converted, though posted limits vary widely by country and road type.
Does this tool account for wind speed or GPS accuracy?
No this is a pure unit conversion between the speed values you enter. It doesn't adjust for how a device measured that speed (GPS drift, wind resistance, etc.), so treat the converted number with the same accuracy as your original reading.