Written by Muneeb Rana · Last updated 26 October 2026
Quick answer: An average speed calculator divides total distance by total time. Add each leg of your trip, decide whether stops count, and it returns the true average. Never average the speeds themselves: driving 30 mph one way and 60 mph back over the same road averages 40 mph, not 45, because you spend longer at the slower speed.
TL;DR
- Average speed = total distance ÷ total time.
- Do not average leg speeds.
- Choose whether stops are included.
- Moving average is always ≥ overall average.
- Multi-leg input supported.
Using the average speed calculator
Enter each leg's distance and time, or one total. Toggle include stops to see the difference between your overall average and your moving average. The moving average excludes time when you were stationary, which is what cyclists and runners usually quote.
The classic trap
Suppose you drive 60 miles at 30 mph (2 h), then return 60 miles at 60 mph (1 h). Total 120 miles in 3 h = 40 mph. Averaging 30 and 60 gives 45, which is wrong because the legs took different amounts of time. The correct average across equal distances is the harmonic mean.
Overall vs moving average
A 100 km drive in 2 h including a 20-minute coffee stop has an overall average of 50 km/h but a moving average of 60 km/h. Car trip computers differ on which they show; check your manual.
Average speed cameras
Some countries enforce limits with average speed cameras that time you between two points; your average over that section must stay under the limit. Wikipedia's article on average speed cameras describes systems in the UK, Australia and parts of Europe. Speedometer PRO does not detect cameras.
Example table
| Distance | Time | Average |
|---|---|---|
| 50 mi | 1 h | 50 mph |
| 50 mi | 1 h 15 min | 40 mph |
| 100 km | 1 h 40 min | 60 km/h |
| 10 km | 50 min | 12 km/h |
| 5 km | 30 min | 10 km/h |
Common mistake
Don't average two speeds directly. Driving 10 miles at 30 mph and 10 miles at 60 mph averages 40 mph, not 45, because you spend longer at the slower speed. Always divide total distance by total time.
Let the app do it
Speedometer PRO's Current Trip card shows average and max speed as you go, and trip history keeps them.
Related: Free speed tools · Speed distance time calculator · Average speed vs max speed · Trip meter: duration, distance, average and max speed · Travel time calculator · MPH guide: speed units explained · Online speedometer: your speed in the browser
Get Speedometer PRO on Google Play · Download on the App Store · Set it up before you move; never handle your phone while driving.
Sources
- Speed (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
- Average speed camera (Wikipedia): en.wikipedia.org (accessed 26 October 2026)
FAQ
How do I calculate average speed?
Divide total distance by total time. For example, 150 km in 2.5 hours gives an average of 60 km/h.
Can I average two speeds?
Only if you spent equal time at each. Over equal distances you need the harmonic mean, which is lower than the simple average.
Do stops count?
For overall average, yes; for moving average, no. Say which one you mean when you compare trips with someone else.
Why is my average so low?
Traffic lights, stops and slow sections pull it down far more than fast stretches push it up, because you spend more time going slowly.
Does Speedometer PRO show average speed?
Yes. The Current Trip card shows average speed alongside duration, distance and max speed.