Cycling calorie calculator
How much did that ride actually cost you? Roughly: an hour at 14 mph (22 km/h) for a 185 lb rider burns about 850 kcal. Calculate it properly here, either from speed and weight using MET values, or, if you ride with a power meter, from your average power, which is the accurate way.
The power-based figure is accurate to within a few percent, because a power meter measures real work. The speed-based figure is an estimate: it knows nothing about wind, climbing or drafting, and those can change the answer by half. Food comparisons are approximate.
How are cycling calories calculated?
The power method rests on physics and physiology rather than estimates:
work [kJ] = power [W] x time [h] x 3.6 kcal = work [kJ] / 4.184 / efficiency (~24%) in practice: kcal ~ power x time x 3.6 (kJ ~ kcal) MET method: kcal = MET x weight [kg] x time [h] (MET by speed, Compendium of Physical Activities: 6.8 up to 10 mph ... 15.8 above 19 mph)
Why is one more trustworthy than the other? A power meter measures the work your legs actually did, so the only approximation left is muscular efficiency, which sits between 22% and 26% for almost everyone; we use 24%. That is where the famous shortcut comes from: kilojoules of work on the pedals and kilocalories burned are numerically almost the same. MET tables instead assign an intensity to a speed, and speed correlates poorly with effort. Wind, hills and sitting in a group change energy cost by tens of percent at identical speed.
Worked example: 1.5 hours at an average of 180 W is 972 kJ of work, so about 970 kcal. The same ride scored from MET tables (187 lb rider, 14 mph, MET 10) gives 1,275 kcal. That 30% gap is exactly why a power meter is the gold standard for counting calories as well as for training.
Burning more, and enjoying it more
Consistency beats intensity: four 45-minute rides a week build a deficit that one long weekend ride never will, and cycling is gentle enough on the joints to keep that up at any starting weight. If you want the training to be structured rather than accidental, start by setting your zones in the FTP calculator, then use the cycling power calculator to see what those watts actually buy you in speed.
Frequently asked questions
- How many calories does an hour of cycling burn?
- It depends on pace and body weight. For a 185 lb (85 kg) rider: an easy hour at 10 mph burns about 580 kcal, a brisk 14-16 mph hour about 850-1,000 kcal, and racing above 19 mph over 1,300 kcal. A lighter rider burns proportionally less. Those figures come from MET tables; a power meter gives a far more accurate answer.
- How do you convert kJ to calories on a bike?
- One to one, near enough. Your muscles turn only about 24% of food energy into work at the pedals, and 1 kcal equals 4.184 kJ. Those two numbers almost cancel, so 1,000 kJ of work recorded by your head unit corresponds to roughly 1,000 kcal burned. That is why the kilojoule figure on a power-meter ride is the most reliable calorie number you will get.
- Why is power more accurate than speed for calories?
- A power meter measures the work your legs do, regardless of wind, gradient or drafting. The same 15 mph can mean 120 W sitting in a group with a tailwind or 250 W alone into a headwind: twice the calories at identical speed, and a speed-based table cannot see the difference.
- Does cycling help you lose weight?
- Yes, and the author of this site lost 66 lb (30 kg) doing it. The lever is consistency rather than any single hard session: three or four rides a week at 600-800 kcal create a weekly deficit that one long ride cannot match. Cycling is also low impact, which makes it sustainable when carrying extra weight.
- Do bike computers and apps overestimate calories?
- Apps that estimate from speed or heart rate are commonly off by 20-30% in either direction, because they infer power indirectly. Head units paired with a power meter are accurate to within a few percent. If calories matter to you, treat app numbers as indicative and compare week to week rather than trusting a single ride.