Speed Converter - mph, km/h, m/s, Knots & ft/s
Convert speed between miles per hour, kilometers per hour, meters per second, knots, and feet per second.
Converted Values
Kilometers per Hour (km/h)
96.5606
Meters per Second (m/s)
26.8224
Knots (kn)
52.1386
Feet per Second (ft/s)
88
How to Convert Speed Units
Speed can be measured in several common units — miles per hour on US road signs, kilometers per hour almost everywhere else, meters per second in physics and science, knots at sea and in aviation, and feet per second in some engineering contexts. This converter treats meters per second as a common base unit: your input is converted to m/s first, then converted from m/s into every other supported unit.
Example
A car traveling at 60 mph is going 60 × 0.44704 = 26.82 m/s, which is about 96.56 km/h, roughly 52.14 knots, and 88 ft/s. Enter 60 with mph selected to see all of these calculated instantly.
Common Use Cases
- Converting a car's speedometer reading between mph and km/h for international travel.
- Converting wind or boat speed between knots and mph or km/h for sailing and weather reports.
- Physics and engineering problems that require SI units (m/s) as an intermediate step.
FAQs
What is a knot, exactly?
A knot is one nautical mile per hour. A nautical mile (1,852 meters) is based on one minute of latitude along a great circle of the Earth, which is why it doesn't divide evenly into miles or kilometers like other speed units do.
Why do aviation and marine speeds use knots instead of mph?
Knots are tied directly to nautical miles, which correspond to minutes of latitude on navigational charts, making distance and speed calculations for navigation more straightforward than converting through miles or kilometers.
How accurate are these conversion factors?
The factors used (for example, 1 mph = 0.44704 m/s exactly, and 1 knot = 0.5144444 m/s) are the internationally defined standard values, so results are accurate to the number of decimal places shown.