Solve speed, distance or time — enter the two you know.
Calculated locally in your browser.
How do you calculate speed, distance or time?
Speed = Distance ÷ Time, Distance = Speed × Time, and Time = Distance ÷ Speed. Enter the two values you know to find the third. For example, travelling 100 km in 2 hours is an average speed of 50 km/h. Note this gives average speed over the whole journey, not instantaneous speed.
Understanding your result
This gives average speed over the whole journey, not instantaneous speed.
Formula and method
Speed = Distance ÷ Time, Distance = Speed × Time, Time = Distance ÷ Speed.
Assumptions and limitations
It calculates average speed over an entire journey, not the instantaneous speed at any moment, and it assumes steady motion in a straight line. It does not account for stops, traffic, changing pace or curved routes, and both inputs must use consistent, compatible units.
Worked example
Travelling 100 km in 2 hours is an average speed of 50 km/h.
How to use this tool
- Enter any two of distance, time and speed.
- Leave the unknown blank.
- Press Calculate.
Common mistakes to avoid
- Mixing units, such as minutes with km/h.
About the Speed Distance Time Calculator
Work out average speed, distance travelled or time taken from the two values you already know.
Who should use this tool
Drivers and cyclists estimating journeys, runners and swimmers checking pace, physics students solving motion problems, and travellers who know two of speed, distance and time and need the third worked out for the whole trip.
Benefits
- Solves for speed, distance or time from the other two
- Gives average speed across a whole journey
- Removes the need to rearrange the formula yourself
- Handles everyday travel and physics problems alike
Practical use cases
- Estimating arrival time for a planned drive
- Working out average running or cycling pace
- Solving a physics motion problem for coursework
- Checking how far you travel at a steady speed
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Frequently asked questions
Can I use minutes?
Enter time in hours (for example 90 minutes = 1.5). The result is in km/h.
Can I mix units like minutes and kilometres?
Your units must be compatible, so decide whether speed is in kilometres per hour or per minute and keep time consistent with it. If distance is in kilometres and you want a speed in km/h, enter time in hours. Convert minutes to hours by dividing by 60 first.
Does this give average or instantaneous speed?
It gives average speed, the total distance divided by the total time for the whole journey. It cannot tell you how fast you were going at a single instant, since real trips speed up and slow down. Travelling 100 km in 2 hours averages 50 km/h regardless of the pace within it.