Guide
How to Calculate Average Speed from Distance and Time
Average speed is total distance divided by total time. Traveling 120 kilometers in 2 hours gives 60 km/h. Use the complete trip time, including stops, if you want the average for the whole journey.
Start with distance ÷ time
Speed answers how much distance you cover per unit of time. For 150 km in 2.5 hours, average speed = 150 ÷ 2.5 = 60 km/h. This does not mean you traveled at exactly 60 km/h at every moment; it summarizes the trip.
Distance is the length of the route traveled, not the straight-line separation between its endpoints. Driving 10 km away and 10 km back covers 20 km even though you finish where you started. Average speed is different from velocity, which also considers direction.
Convert minutes to decimal hours
This tool takes time in hours. Divide minutes by 60: 30 minutes is 0.5 hours, 15 minutes is 0.25 hours, and 45 minutes is 0.75 hours. For 1 hour 30 minutes, enter 1.5, not 1.30.
Example: a cyclist covers 12 km in 45 minutes. Time = 45 ÷ 60 = 0.75 hours. Average speed = 12 ÷ 0.75 = 16 km/h. Entering 45 in the hours field would describe a completely different journey.
Convert km/h to meters per second
Divide km/h by 3.6 to get m/s. There are 1,000 meters in a kilometer and 3,600 seconds in an hour, so 1 km/h = 1,000/3,600 m/s. At 60 km/h, the equivalent speed is about 16.67 m/s.
To go the other way, multiply m/s by 3.6. A speed of 10 m/s equals 36 km/h. The calculator displays both km/h and m/s from the same distance and time inputs; it does not accept miles directly.
Why averaging two speed readings can be wrong
Suppose you travel 60 km at 30 km/h, then 60 km at 60 km/h. The first leg takes 2 hours and the second takes 1 hour. Total distance is 120 km, total time is 3 hours, so average speed is 40 km/h, not (30 + 60) ÷ 2 = 45 km/h.
The simple average of two speeds works when you spend equal time at each speed. For a journey with several legs, add their distances and times separately, then divide. Decide whether to include breaks: including them gives a trip average, while excluding them gives a moving average.
Calculate your journey's average
Enter Distance (km) and Time (hours). The Speed Calculator returns average speed in km/h and m/s. Time must be greater than zero; a zero-distance trip over a positive time has zero average speed.
For planning, rearrange the formula: time = distance ÷ speed, or distance = speed × time. Those are hand calculations rather than extra modes in this tool. Traffic, breaks, and changing conditions mean an average-speed estimate is not a guaranteed arrival time.
Try it yourself
Put this guide into practice with our free Speed Calculator — no sign-up, no download.
Open the Speed Calculator