Key takeaways
- Speed = Distance ÷ Time, in km/h for this calculator.
- Convert minutes to hours by dividing by 60 before dividing.
- This formula gives average speed, not top speed.
- Time must be greater than zero to calculate a speed.
In this guide
What is speed?
Speed measures how quickly something covers distance. It's the same idea whether you're timing a car on a highway, a cyclist on a route, or a train between two stations.
Why does speed matter?
Speed is how we plan almost every journey — estimating arrival times, comparing routes, and setting safe limits on roads. It's one of the most-used calculations in everyday life.
A road trip covering 150 km in 3 hours, including a coffee stop, averages 50 km/h overall, even if the car spent long stretches doing 100 km/h on the highway.
The formula
| Symbol | What it means | Example |
|---|---|---|
| Speed | The average speed, in kilometres per hour (km/h) | 50 km/h |
| Distance | The distance travelled, in kilometres (km) | 150 km |
| Time | The time taken, in hours (h) | 3 h |
How to calculate speed step by step
- 1Find the total distance. Measure it in kilometres.
- 2Find the total time. Measure it in hours, converting minutes by dividing by 60.
- 3Divide distance by time.
Distance ÷ Timegives you the speed. - 4Write the answer in km/h. That's the average speed for the whole trip.
Try the calculator below with your own distance and time to see every step worked out.
Try it yourself
Pre-filled with the example — change any value.
Common mistakes to avoid
- Using a time of zero. You need some positive amount of time to calculate a speed.
- Confusing average speed with top speed. This formula gives the average over the whole trip, not the fastest moment.
- Mixing km and m. Keep distance in kilometres for this calculator, or convert first.
Tips and tricks
- Working backwards from speed to time? Divide distance by speed:
Time = Distance ÷ Speed. - For distances in metres and time in seconds, the velocity calculator uses the same idea with more precise units.
- Once you know your speed, the acceleration calculator tells you how quickly that speed itself is changing.
Where you'll use it in real life
- Road trips: estimating how long a journey will take before you set off.
- Sport: tracking a runner's or cyclist's average pace over a race.
- Public transport: working out a train or bus's average speed between two stops.
- Delivery and logistics: planning realistic delivery windows based on distance and expected traffic.
Quick summary
To find average speed, divide the total distance in kilometres by the total time in hours. Remember to convert minutes to hours first, and remember this gives an average, not a top speed. Use the calculator above to check your own trip.
Worked example
You drive 150 km on a road trip and the journey takes 3 hours, including a short stop. What is your average speed?
- 01Speed = Distance ÷ Time
- 02Speed = 150 km ÷ 3 hours
- 03Speed = 50 km/h
These numbers are pre-filled in the calculator above.
Frequently asked questions
How do I calculate average speed?
Divide the total distance travelled by the total time taken: Speed = Distance ÷ Time. For km and hours, the answer is in km/h.
How do I convert minutes into hours for this formula?
Divide the number of minutes by 60. For example, 30 minutes is 0.5 hours, and 45 minutes is 0.75 hours.
What's the difference between speed and velocity?
Speed is just how fast something moves. Velocity is the same idea but also states a direction, such as 60 km/h north.
Does this formula give my top speed?
No, it gives your average speed over the whole distance and time, including any stops or slow sections along the way.
