Split from speed
Forty kilometres at 30 km/h is 1:20:00. The arithmetic is distance divided by speed, but the useful part is the comparison table: the same 40 km at 32 km/h is 1:15:00, and at 28 km/h it is 1:25:43. Each km/h is worth roughly 2 minutes 40 seconds over an Olympic bike leg.
Speed from a target split
If you know the split you need — say 2:30 for a 90 km leg — the calculator returns the average speed required, which is 36 km/h. That is a much more actionable number than a split, because speed is what you can control on the road.
Average speed is not constant
Hills, wind and corners mean your average is lower than the speed you hold on the flat. A rolling course typically costs 1–2 km/h compared with a flat one at the same effort. Use the average as a target, but pace by effort or power on the day.
Frequently Asked Questions
What is a good bike average?
25–30 km/h is typical for age-groupers; 32–35 km/h is strong; above 38 km/h is competitive.
Does drafting change the split?
Enormously — 20–30% less power at the same speed. Most age-group races are non-drafting, so the calculator assumes solo riding.
How accurate is the target-speed calculation?
It is exact arithmetic. Whether you can hold that speed for the distance is the physiological question.
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