Speed Calculator
Solve for speed, distance or time, in any combination of units.
About Speed Calculator
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).
Formulas
Speed
Speed = Distance ÷ Time
- v
- Speed
- d
- Distance
- t
- Time
Distance
Distance = Speed × Time
Time
Time = Distance ÷ Speed
Worked example
With the default values below, Speed Calculator returns Result of 66.6667. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Solve Forone of Speed, Distance, Time
- Speed
- Speedaccepts 0–1,000,000
- 60
- Speed Unitone of mph (miles per hour), km/h (kilometres per hour), m/s (metres per second), ft/s (feet per second), knots (kn)
- mph (miles per hour)
- Distanceaccepts 0–1,000,000,000
- 100
- Distance Unitone of Miles (mi), Kilometres (km), Metres (m), Feet (ft), Yards (yd), Nautical miles (nm)
- Miles (mi)
- Timeaccepts 0–1,000,000
- 1.5
- Time Unitone of Hours (hr), Minutes (min), Seconds (s), Days (day)
- Hours (hr)
- Result Speed Unitone of mph, km/h, m/s, ft/s, knots
- mph
- Result Distance Unitone of Miles (mi), Kilometres (km), Metres (m), Feet (ft), Nautical miles (nm)
- Miles (mi)
- Result Time Unitone of Hours (hr), Minutes (min), Seconds (s), Days (day)
- Hours (hr)
Results
- Result
- 66.6667
- Speed (mph)
- 66.667
- Speed (km/h)
- 107.290
- Distance (m)
- 160,934.40
- Time (s)
- 5,400.00
Step by step
- 1Convert distance to metres= 160934.4 m
- 2Convert time to seconds= 5400 s
- 3Speed = distance ÷ time= 29.8027 m/s = 66.6667 mph
Assumptions and limits
- The result is derived only from the 10 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How do I convert 60 mph to km/h?
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.
What is a knot?
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.
If I drive 100 miles at 65 mph, how long does it take?
Select 'Solve for Time', enter distance=100 miles, speed=65 mph. Result: 100/65 ≈ 1.538 hours = 1h 32m 18s.
Can this solve for average speed over a whole journey?
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.