Choose the unknown before entering numbers
Average speed equals distance divided by time. Rearranging the same relationship gives moving time = distance ÷ moving average speed, and distance = moving average speed × moving time. Use hours with kilometres per hour or miles per hour; convert 30 minutes to 0.5 hours, not 0.30 hours.
The cycling calculator offers these three modes. Choose the quantity you want, enter the other two and use the result as an arithmetic estimate. The speed input is a whole-ride average assumption, not a promise that you can maintain one speed on every section.
- Choose Calculate time when you know the planned distance and an assumed moving average.
- Select kilometres and km/h, or miles and mph; do not mix a mile distance with a km/h speed.
- Enter moving time as hours, minutes and seconds when calculating speed or distance.
- Add stops in the separate break-minutes field. Calculate and compare moving and total duration.
- Repeat with a lower assumed average or longer breaks to see how the plan changes.
Example: 20 kilometres with a 15-minute stop
Suppose a ride covers 20 km with 1 hour of moving time and 15 minutes stopped. Moving average is 20 ÷ 1 = 20 km/h. The total trip lasts 1.25 hours, so overall average is 20 ÷ 1.25 = 16 km/h. Both numbers describe the same trip using different time definitions.
In Calculate speed mode, enter 20 km, 1 hour and 15 break minutes. The results should show 20 km/h moving average, 1 hour 15 minutes total time and 16 km/h overall average. Entering 1 hour 15 minutes as moving time and then adding the stop again would count the break twice.
Example: planning 30 kilometres at 15 km/h
Moving time is 30 ÷ 15 = 2 hours. Add a planned 20-minute stop and allow 2 hours 20 minutes for the whole trip. Overall average becomes 30 ÷ (2 + 20/60), approximately 12.86 km/h. These are worked arithmetic examples, not recommended targets for every cyclist.
Use Calculate time mode with 30 km, 15 km/h and 20 break minutes to reproduce this result. If the moving average were 12 km/h instead, moving time would be 2 hours 30 minutes before breaks. Terrain, junctions, traffic and weather can change actual progress; a calculator does not inspect the route or predict those conditions.
Convert miles and kilometres together
This tool uses the international mile, which NIST lists as exactly 1,609.344 metres. Therefore 10 miles equals 16.09344 kilometres, and 10 mph equals 16.09344 km/h. When both distance and speed use the same conversion factor, the calculated time stays the same.
For example, 10 miles at 10 mph takes 1 hour, just as 16.09344 km at 16.09344 km/h does. Change the unit selector to compare displays. Short decimal displays are rounded; the tool retains precision for calculations. A rounded label is not an extra measurement of the trip.
Combine segments by adding distance and time
Do not average segment speeds directly unless the time intervals are equal. Riding 10 km at 10 km/h takes 1 hour; another 10 km at 20 km/h takes 0.5 hours. Total distance is 20 km and total moving time is 1.5 hours, giving approximately 13.33 km/h, rather than (10 + 20) ÷ 2 = 15 km/h.
After a ride, compare like with like: a recorder’s moving-time rules, auto-pause behaviour and elapsed-time definition can differ. Read what the recording app reports before comparing its average with your calculation. For actual iPhone recording, use the linked HappyRide app workflow; this page only calculates the values you enter.