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Calculators
Quick answers from the same physics and research as our race tools. Every answer shows its working and its sources, so you can check it.
Free, no account, nothing saved. Your numbers stay in the address bar, so you can bookmark or share a result.
Energy and fuel
Energy of an effort
Watts and time to kJ of work and kcal burned, with the gross efficiency it rests on.
Carb loading
Grams of carbohydrate a day to load before a race, from a meta-analysis of 181 studies.
Carbohydrate budget
Muscle and liver glycogen against what a ride burns: when you run empty, and what to eat or how much to ease off.
Caffeine dose
Caffeine in mg for your body weight: the dose that helps endurance, and EFSA's safe limits.
Speed and physics
Speed from power
Speed from watts, weight, CdA, Crr, gradient and wind, with where the power goes. The physics behind our race pacing.
Climb time and VAM
Time up a climb from length, gradient, watts and weight, with VAM and W/kg.
Grams, aero or watts?
Time saved by losing a kilo, cutting drag, a faster tyre or more watts, on flat, rolling and mountain courses.
Descent speed
Top coasting speed on a descent by gradient, weight and position, from wind-tunnel data.
Corner speed and lean
Lean angle for a corner's radius and your speed, and the top speed through it at each lean.
Drafting savings
Watts saved riding in a line or a bunch at your speed, from wind-tunnel-checked simulations of pelotons.
Gearing
Speed, development and gear inches for a chainring and cog, and the steepest gradient you can hold a cadence on.