Average cycling speed:
distance, time and the stops in between

Speed from distance and time

Average cycling speed answers a plain question: how fast did I travel over the whole ride? Take the total distance and divide it by the total time. If you covered 45 kilometres in two and a half hours, your average speed was 18 kilometres per hour.

It is the number on your cycle computer's summary screen, and the figure you use to plan: how long will a 100 km ride take, what pace do I need for a century, will I reach the café before it closes. A little care with units and time makes it reliable.

The simple formula also leaves three traps that catch plenty of riders: using the wrong time, averaging speeds instead of computing from totals, and mixing units.

The formula and its rearrangements

Convert miles per hour by dividing km/h by 1.609, so 18 km/h is 11.18 mph. Going the other way, multiply miles per hour by 1.609.

Moving time versus elapsed time

Stops change the answer. Your 45 km ride took 2.5 hours from start to finish, but 10 minutes at a junction, a puncture and a coffee stop took 30 minutes of that time standing still. If your computer logged 2 hours 20 minutes of actual riding, your moving average was 45 ÷ 2.333 = 19.29 km/h.

Both numbers are valid and mean different things. Elapsed speed tells you how long the whole outing takes, which is what you need for planning a schedule. Moving speed tells you how fast you actually ride, which is what you compare between rides or with friends.

Why you cannot average two speeds

A frequent mistake is taking the mean of the speeds on separate parts of a ride. Say you ride 20 km uphill at 12 km/h and 20 km back down at 36 km/h. The mean of the two speeds is 24 km/h, but that is not your average speed.

Because you spend more time at the slower speed, it counts for more. This is also why a headwind on the way out costs more than a tailwind returns, and why average speeds are always lower than the speed you feel while rolling.

Planning a ride from a target speed

Planning uses the formula in reverse. Say you want to ride 160 km in 8 hours of moving time. You need 160 ÷ 8 = 20 km/h. Add rest stops: with an hour of breaks the elapsed time becomes 9 hours and the elapsed average falls to 17.8 km/h.

1. 1Choose a realistic moving speed from recent rides on similar terrain.
2. 2Divide distance by that speed for the moving time.
3. 3Add time for stops, food and mechanical problems, which often total 10 to 15 percent of a long ride.
4. 4Add a buffer for hills and wind, and plan the start time from the finish you want.

Terrain is the biggest variable. A route with 1,500 metres of climbing is slower than a flat one with the same length, even at the same effort, so use your past average on similar roads, not on your quickest rides.

Using speed targets in real events

Long-distance events state their pace as a minimum average. Randonneuring rides of 200 km, for example, allow 13.5 hours, which works out at 200 ÷ 13.5 = 14.8 km/h including every stop. That is a modest riding speed, but it is an elapsed average, so a long café break needs to be paid for by riding faster elsewhere.

The same arithmetic applies to commuting. A 12 km trip at an 18 km/h moving average takes 40 minutes, and each traffic light adds to the elapsed time without changing the speed shown on the cycle computer. If your door-to-door time matters, record that total and track it directly.

Finally, take the figure from your device with a pinch of salt. GPS smoothing, auto-pause settings and wheel-size calibration all shift the displayed average slightly, so a difference of 0.1 or 0.2 km/h between rides is not a real change in fitness.

Speed from cadence, gearing and wheel size

Your speed on the bike also follows from how fast you pedal and the gear you are in. For a given wheel, speed is cadence times gear ratio times the wheel's circumference.

What drags the average down

• Wind, which is felt far more in the headwind than it is rewarded in the tailwind.
• Climbing and gradient changes, even when the net elevation is zero.
• Stops at junctions, signals and crossings, especially in cities.
• Road surface and tyre choice. Rough tarmac and soft tyres add rolling resistance.
• Group size and drafting. Riding in a group can lift the average of every rider in it.

When comparing rides, compare like with like: the same route, the same conditions and the same time basis. A calculator makes the conversions quick, but it cannot adjust for a headwind you did not record.