Training tools
Five quick calculators to prepare a race, pick a bike size and a gear, train at the right intensity and drink enough.
Estimates from published rules of thumb, not measurements. Nothing you type is saved or sent: everything is calculated in your browser.
Running pace
Enter a distance and a time to get your pace, and an estimate for the other race distances.
- Pace
- 5:00 /km
- Speed
- 12 km/h
Estimated times on other distances
- 5 km23:59
- 10 km50:00
- Half marathon1:50:19
- Marathon3:50:01
Riegel's formula (1981). It assumes you are trained for the distance: on a marathon, the estimate is often optimistic.
Bike frame size
Measure your inseam barefoot, back against a wall, from the floor to the crotch.
Type of bike
Enter an inseam between 55 and 105 cm.
Inseam × 0.70 (road), × 0.66 (city) or × 0.226 (mountain bike, in inches). Every brand has its own geometry: check its size chart before buying.
Heart-rate zones
Your age gives an estimated maximum. If you know your real maximum, enter it instead.
Enter an age between 12 and 90.
Maximum estimated with Tanaka's formula (208 − 0.7 × age). With a resting heart rate, zones use the heart-rate reserve (Karvonen). This does not replace medical advice: see a doctor before any intense training.
Gear and speed
Your chainring and cog, your cadence and your tyre: the speed you ride at.
Tyre
- Speed
- 37.9 km/h
- Distance per pedal turn
- 7.02 m
Cadence × (chainring ÷ cog) × wheel circumference. The circumferences are those cycle computers use; the real one varies slightly with pressure.
Sweat rate
Weigh yourself just before and just after a session, in the same clothes, after drying off. Add what you drank.
Enter both weights (30 to 200 kg) and a duration (15 to 600 min).
Each kilogram lost is about one litre of sweat (field method of the American College of Sports Medicine). Sweat varies with heat, effort and the person: measure it on several sessions. These are estimates, not medical advice.