Speed Distance Time Calculator
Solve for speed, distance or time.
Enter any two of the three.
Results update as you type.
How it works
Speed, distance, and time are locked together by one simple relationship, and this speed distance time calculator lets you enter any two of them to solve for the missing value automatically. Whether you know how far you travelled and how long it took, or you know your speed and need to work out arrival time, the tool rearranges the equation for you and even converts the speed into kilometres per hour, miles per hour, and metres per second. This matters for everyday planning and technical work alike: drivers estimating journey times, runners tracking pace, pilots and sailors plotting routes, and physics students solving motion problems all depend on it. A dependable speed distance time calculator removes the guesswork of dividing or multiplying under time pressure and the risk of mixing up which quantity to solve for. The formula works because speed is by definition the distance covered in a given time, so the three values form a fixed triangle where knowing two always determines the third. By offering multiple speed units side by side, a speed distance time calculator bridges metric and imperial systems in one step, making it useful for travel, sport, engineering, and classroom exercises around the world.
speed = distance ÷ time
Speed is defined as the distance travelled per unit of time, so dividing distance by time gives the average rate of travel. Rearranging the same relationship lets you find distance as speed times time, or time as distance divided by speed. The formula works because it is the definition of average speed itself, assuming steady motion over the interval, which is why any two of the three quantities fix the third.
Source:Standard physics (kinematics)
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter your values in the fields above.
- 2
Adjust the options
Adjust speed, distance and time if they apply — sensible defaults are already set.
- 3
Read your result
Speed updates instantly as you type — no button to press.
Frequently asked questions
Which two values do I need to enter?
Enter any two of the three quantities — speed, distance, or time — and the calculator solves the remaining one. For example, supply distance and time to find speed, or supply speed and time to find distance. It also converts the resulting speed into miles per hour and metres per second. If you enter only one value the relationship is undetermined and no unique answer can be produced.
Does this give average speed or instantaneous speed?
It gives average speed over the whole journey, calculated as total distance divided by total time. It does not capture moment-to-moment changes, so if you sped up and slowed down along the way, the figure represents the constant speed that would have covered the same distance in the same time. Instantaneous speed, like a speedometer reading, requires measuring distance over a very small time interval instead.
What units does the calculator use?
Speed is entered in kilometres per hour, distance in kilometres, and time in hours. The primary speed result appears in km/h, and the calculator also converts it to miles per hour and metres per second for convenience. To convert time such as 90 minutes into hours, divide by 60 to get 1.5 hours before entering it, which keeps every result consistent and accurate.
How do I convert between km/h, mph, and m/s?
To convert kilometres per hour to miles per hour, multiply by about 0.6214. To convert km/h to metres per second, divide by 3.6. The calculator performs both conversions automatically, showing all three units side by side so you never have to do the arithmetic yourself. This is especially handy when comparing metric road signs with imperial vehicles or converting figures for a physics problem.
How do I handle time given in minutes?
Convert minutes into hours before entering the time, because the calculator expects hours. Divide the number of minutes by 60: 30 minutes becomes 0.5 hours, and 90 minutes becomes 1.5 hours. Entering minutes directly would make the speed appear sixty times too small. Once the time is in hours, the speed, distance, and unit conversions all come out correctly for your journey.