Speed, Distance and Time Calculator
Find the speed, distance or travel time when you know the other two.
About this tool
Choose what you want to find, then enter the other two values. The calculator uses speed = distance ÷ time and its rearrangements, accepts times like 1:45:00, 45:30 or a number of minutes, and converts between km/h, mph and metres per second.
Speed, distance and time are linked by one simple rule, so if you know any two you can work out the third. Use this calculator to find your average speed on a trip, how far you will get in a set time, or how long a journey will take at a given speed. It works in kilometres or miles, accepts times in hours, minutes and seconds, and shows the pace and the speed in other units too.
How to use the Speed, Distance and Time Calculator
- Choose whether you want the speed, the distance or the time.
- Pick kilometres or miles.
- Enter the two values shown. Type times as 1:45:00 for hours, minutes and seconds, 25:30 for minutes and seconds, or just a number of minutes.
- Read the answer, the same result in other units and the pace.
A 150 km drive in 1 hour 45 minutes
1 hour 45 minutes is 1.75 hours, and 150 ÷ 1.75 = 85.7 km/h, which is about 53.3 mph. Turned around, at an average of 100 km/h the same 150 km would take 150 ÷ 100 = 1.5 hours, or 1:30:00. Remember that an average includes stops and slow sections, so it is usually well below the speed limit.
The speed triangle
The three formulas are speed = distance ÷ time, distance = speed × time and time = distance ÷ speed. The usual mistake is mixing units: if speed is in km/h, the time must be in hours, so 45 minutes is 0.75 hours, not 0.45. This calculator converts times for you. To change km/h to metres per second, divide by 3.6; to change km/h to mph, divide by 1.609. Average speed is total distance divided by total time, which is not the same as averaging two speeds: driving 60 km at 60 km/h and 60 km at 120 km/h takes 1.5 hours, an average of 80 km/h, not 90 km/h.
Frequently asked questions
How do I calculate average speed?
Divide the total distance by the total time, with the time in hours. 240 km in 3 hours is 80 km/h.
How long will it take to drive 300 km at 120 km/h?
300 ÷ 120 = 2.5 hours, which is 2 hours 30 minutes, not counting stops or traffic.
How do I convert km/h to m/s?
Divide by 3.6. So 90 km/h is 25 metres per second, and to go back you multiply by 3.6.
Can I use this for running or cycling?
Yes. Enter a distance and your finishing time to get your average speed and pace per kilometre or mile. The pace calculator also predicts race times.