Convert between mph, km/h, m/s, ft/s, and knots. Enter a speed and pick the units.
Usage Tip
Quick driving conversions: multiply mph by 1.6 for km/h; multiply km/h by 0.62 for mph.
result = value × (from factor ÷ to factor)
A knot is one nautical mile per hour, used in aviation and at sea.
Knots are nautical: 1 knot ≈ 1.151 mph ≈ 1.852 km/h.
Highway anchor: 60 mph ≈ 97 km/h; 100 km/h ≈ 62 mph.
Speed is distance divided by time, and units differ by region and field. One mile per hour equals 1.609 kilometers per hour, or about 0.447 meters per second. One meter per second is exactly 3.6 kilometers per hour, which makes that conversion easy to do by hand.
Knots are used in shipping and aviation. One knot is one nautical mile per hour, or exactly 1.852 kilometers per hour, which is about 1.151 miles per hour. Feet per second turns up in ballistics and some engineering work. When converting for a speed limit or a vehicle, round sensibly, since the conversion factors carry more decimals than the original measurement usually does.