Solve for speed, distance or time, in any combination of units.
Speed, distance and time are related by speed = distance ÷ time. Knowing any two lets you compute the third. This calculator works entirely in SI (metres and seconds) internally, then converts to your chosen output unit. Unit conversion tables are exact by definition (1 mile = 1609.344 m; 1 knot = 1852 m/hr).
Speed
Speed = Distance ÷ Time
Distance
Distance = Speed × Time
Time
Time = Distance ÷ Speed
60 mph × 1.609344 = 96.56 km/h. Alternatively, enter speed=60, speedUnit=mph, solve for Distance over 1 hour and read the km result — but the unit converter is simpler for a pure conversion.
A knot is 1 nautical mile per hour. One nautical mile = 1852 metres, defined as 1 arc-minute of latitude on the Earth's surface. It's the standard unit in aviation and marine navigation.
Select 'Solve for Time', enter distance=100 miles, speed=65 mph. Result: 100/65 ≈ 1.538 hours = 1h 32m 18s.
Yes — enter total distance and total time to get the average speed. Note that average speed is total distance / total time, not the arithmetic mean of the speeds at each segment.