Motion
Enter any two of speed, distance, or time to solve the third. Supports kilometers and miles.
Hours
Minutes
Solved Speed
66.67km/h
Travel 100 km in 1h 30m
Speed = distance / time. Use consistent units for accurate results.
A speed calculator is a tool that computes speed, distance, or time using the relationship speed = distance / time. Whether you're planning a road trip, analyzing running pace, or working through physics problems, this tool eliminates manual calculation and unit conversion errors.
The calculator uses the basic motion formula: speed = distance / time, which can be rearranged to solve for any missing variable. Provide two of the three values (speed, distance, time) and the tool instantly calculates the third. Results display in multiple units: speed in km/h, mph, and m/s; distance in kilometers and miles; time in hours and minutes.
Speed = Distance / Time; Distance = Speed × Time; Time = Distance / SpeedThese three formulas are algebraic rearrangements of the same relationship. If you travel 100 km in 2 hours, your speed is 100 / 2 = 50 km/h. If you travel at 50 km/h for 2 hours, you cover 50 × 2 = 100 km. If you need to cover 100 km at 50 km/h, it takes 100 / 50 = 2 hours.
| Input | Result | Notes |
|---|---|---|
| Distance 100 km, Time 1h 30m | Speed: 66.67 km/h (41.4 mph, 18.52 m/s) | A typical highway drive at reasonable speed. |
| Speed 60 mph, Distance 150 miles | Time: 2 hours 30 minutes | Common road trip calculation for US highway driving. |
| Speed 10 m/s, Time 45 minutes | Distance: 27 kilometers (16.78 miles) | Physics or running pace calculation. |
You need at least two values (speed, distance, or time) to solve for the third. If you only know one, the calculator cannot compute a unique answer.
km/h and mph are used for vehicles; m/s is the SI unit used in physics and engineering. The calculator shows all three so you can use whichever is relevant to your context.
Yes. Measure the total distance traveled and total time elapsed (including stops), then calculate total distance / total time. This gives the average speed for the entire trip.
The calculator uses full floating-point precision (15-17 significant digits). For real-world applications like driving or running, this is more precision than you need.
Calculate each leg separately, then sum total distance and total time to find the overall average speed using this tool.
Divide km/h by 1.609 or multiply mph by 1.609. The calculator does this automatically and displays both units.