Speed Converter
Convert speed between km/h, mph, m/s, ft/s and knots.
Results update as you type.
About this calculator
A speed converter changes a rate of travel between metric (m/s, km/h), imperial (mph, ft/s) and the knot used at sea and in aviation. All values pass through meters per second as the base unit, so every pair converts in both directions.
The anchor relationships are 1 m/s = 3.6 km/h, 1 mph = 1.609344 km/h, and 1 knot = 1.852 km/h (one nautical mile per hour). Because km/h and mph both derive from the metre and the mile, converting between them is a single fixed ratio.
Worked example: to convert 100 km/h to mph, divide by 1.609344 (or multiply by 0.621371), giving about 62.14 mph. To convert 60 mph to m/s, multiply by 0.44704, giving about 26.8 m/s. The "all units" table lists your speed in every unit at once, useful for driving, running, sailing and weather.
Frequently asked questions
How do I convert km/h to mph?
Divide the km/h value by 1.609344, or multiply by about 0.621371. So 100 km/h is roughly 62.14 mph.
What is a knot?
A knot is one nautical mile per hour, about 1.852 km/h or 1.15 mph. It is the standard speed unit for ships and aircraft.
How fast is 60 mph in m/s?
One mph is 0.44704 m/s, so 60 mph is about 26.8 meters per second.
How do I convert m/s to km/h?
This speed converter multiplies meters per second by 3.6, so 10 m/s is 36 km/h; to go back it divides km/h by 3.6.
How do I convert mph to km/h?
Multiply mph by 1.609344. So 60 mph is about 96.6 km/h, and 70 mph is about 112.7 km/h. Divide by the same factor to go from km/h to mph.
What is a good running or walking pace in these units?
A brisk walk is roughly 5 km/h (about 3.1 mph), and a typical jogging pace is around 10 km/h (about 6.2 mph). Convert any pace between units to compare against a target.
Why do ships and planes use knots?
A knot is one nautical mile per hour, and a nautical mile equals one minute of latitude, so knots map neatly onto navigation charts and great-circle distances.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/speed/curl
curl "https://calculator.free/api/v1/speed/?amount=1&from=kmh&to=mph"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/speed/?" + new URLSearchParams({
"amount": "1",
"from": "kmh",
"to": "mph"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.