Cycling calories calculator
This cycling calories calculator converts mechanical work in kilojoules into calories burned, either from a kJ figure your head unit already shows or from average power and ride duration. Enter what you know, and get calories along with the equivalent grams of carbohydrate that energy roughly represents, a quick way to plan food and drink around a ride's real cost.
Calories burned
797kcal
How it works
Power meters and head units report work in kilojoules, mechanical energy delivered to the pedals, which converts to dietary calories by dividing by 4.184 kilojoules per kilocalorie and then by the roughly 24% efficiency of the human body turning food energy into pedalling power, so 1 kJ of work corresponds to close to 1 kcal burned.
When you know average power and duration instead of a kJ total, kilojoules are simply average watts times seconds divided by 1000, the same relationship a power meter uses internally to accumulate its own kJ reading over a ride.
The carbohydrate equivalent divides total kcal by 4, the standard dietary energy density of carbohydrate, giving a rough sense of how much of that energy expenditure a carb-based fuelling strategy would need to replace.
Frequently asked questions
How many calories does cycling burn per kJ?
Close to 1 kcal burned for every kJ of mechanical work, since dividing kJ by the physical conversion factor and by roughly 24% metabolic efficiency very nearly cancel out. It's why many riders use their head unit's kJ number as a quick calorie estimate.
Is the kJ reading on my head unit the same as calories burned?
Almost, but not exactly: kJ measures mechanical work at the pedals, while calories burned also account for the body's metabolic efficiency in producing that work. The two numbers end up close because the conversion and efficiency factors happen to roughly offset.
How do I estimate calories without a power meter?
Use the average power and time option here with an estimated average power for the ride, based on effort level and past rides with a meter if you have one. It's less precise than a direct power meter reading but still a reasonable ballpark.
Related tools
- FTP zones calculatorCalculate your cycling FTP from a known value or a 20-minute power, free, with the seven Coggan training zones in watts.
- Watts per kg calculatorWork out your cycling power-to-weight ratio and rider category for free, using the Coggan power profile for men and women.
- Speed to power calculatorEstimate the power needed to hold a cycling speed, free, with gravity, rolling and aero components and a full speed table.
- Climb time calculatorPredict climb time, speed and VAM from length, elevation gain and power, free, with a table across a range of power outputs.
Overload shows energy per ride
Overload shows kJ and estimated calories for every ride you log automatically. Free on iOS and Android.