Speed, distance, and time are one family: speed = distance ÷ time, distance = speed × time, time = distance ÷ speed. Pick which unknown to solve, enter the other two, and choose km/mi and km/h or mph. The result is average speed over the whole trip — not a speed-limit or GPS live reading.
Speed60 km/h
Speed37.28 mph
Distance120 km
Distance74.565 mi
Time (H:MM)2:00
Time (decimal hours)2
How this calculation works
Internally everything is converted to kilometers and hours (1 mile = 1.609344 km). Then the missing quantity is computed and converted back.
Time inputs are hours + minutes. 1 hour 30 minutes is 1.5 hours. The clock output is H:MM for the solved duration.
When solving speed you need distance and time. When solving distance you need speed and time. When solving time you need distance and speed.
This is uniform motion. It does not add rest stops, wind, or acceleration. For running pace per km, use the running-pace calculator.
Worked example
120 km in 2 hours → 60 km/h (37.28 mph). 50 km/h for 1 hour 30 minutes → 75 km. 60 mph over 93.21 miles → about 1:33.
Frequently asked questions
Is this average or instantaneous speed?
Average for the numbers you typed. Stopping for an hour on a 2-hour clock still uses 2 hours in the denominator if you enter 2.
km/h vs mph?
Pick the unit that matches the number. The other unit is always shown in the results.
Can I mix km distance with mph speed?
Yes when solving time: distance unit and speed unit are independent and converted internally.
What about nautical miles?
Not on this page. 1 knot = 1.852 km/h if you convert by hand first.
Negative time?
Inputs must be positive. Invalid combinations return no result.