Speed Converter
Highway signs in km/h, wind reports in knots, a treadmill in mph — pick your unit, type the number, and the rest fill in.
How it works
Everything is measured against meters per second first. Your entry gets turned into m/s, then divided back out into km/h, mph, knots, and ft/s. One value updates the whole grid, no button to press.
The tricky pairs are the ones people actually need. A knot is one nautical mile per hour, which lands at 1.852 km/h, and mph to km/h is a multiply-by-1.609. Those two trip up more people than any metric conversion.
A handy gut check: 100 km/h is roughly 62 mph, and 1 m/s is about 3.6 km/h. If a result looks way off, you've probably got the from-unit set wrong.
Frequently asked questions
How fast is 100 km/h in mph?
It's about 62.14 mph. The factor is 0.621371, so any km/h figure times that gives you miles per hour. Set the unit to km/h and the mph row shows the exact number.
What's a knot in km/h?
One knot equals 1.852 km/h exactly, because a knot is one nautical mile per hour and a nautical mile is 1,852 meters. Sailors and pilots stick with knots for that clean tie to latitude.
How do I convert m/s to km/h?
Multiply by 3.6. So 10 m/s is 36 km/h. It's one of the cleaner conversions since there's no messy decimal factor involved.