Calories Burned
Estimate calories burned by MET, weight, and time.
About the Calories Burned
Calories burned during exercise depend mostly on your weight and how hard you work, not on the machine's display.
How to use it
- Enter your weight.
- Choose the activity.
- Enter how long you did it for.
The formula
Calorie burn is estimated from METs — metabolic equivalents. One MET is the energy you use sitting still, and every activity is rated as a multiple of it.
Calories per minute = METs × 3.5 × kg ÷ 200
Total = Calories per minute × Minutes
The 3.5 is oxygen consumption in millilitres per kilogram per minute at rest, and the 200 converts millilitres of oxygen into kilocalories. Both are population averages, which is the honest headline: this is a reasonable estimate for a group and a rough one for any individual.
Weight appears directly in the formula, so a heavier person burns more doing the same activity — moving more mass costs more energy. Fitness works the other way: a trained runner uses less energy at a given pace than an untrained one, which is exactly what improved efficiency means.
Worked examples
| Activity | METs | Weight | 30 minutes | 60 minutes |
|---|---|---|---|---|
| Walking, 3.5 mph | 4.3 | 70 kg | 158 kcal | 316 kcal |
| Swimming laps, moderate | 7.0 | 70 kg | 257 kcal | 515 kcal |
| Cycling, moderate | 8.0 | 70 kg | 294 kcal | 588 kcal |
| Running, 6 mph | 9.8 | 70 kg | 360 kcal | 720 kcal |
A useful reality check sits in these numbers: half an hour of running burns roughly 360 calories, which is about one blueberry muffin. This is not an argument against exercise — the cardiovascular, metabolic and mental benefits are substantial and well evidenced. It is an argument against treating exercise as a licence to eat, because the arithmetic simply does not favour it.
Common mistakes
- Trusting the number on the machine. Cardio machines commonly overestimate, sometimes by 20% or more, and many do not know your weight. Treat any displayed figure as an optimistic approximation.
- Forgetting you would have burned calories anyway. This is gross expenditure, including the resting metabolism you would have used sitting on the sofa. Net additional burn is lower — for light activity, noticeably so.
- Applying one MET value to a whole session. Intensity varies. An hour at the gym is rarely an hour at a single MET level, and warm-ups, rests and gentle stretches are worth far less than the headline activity.
- Eating back every estimated calorie. Since these figures usually run high and food labels usually run low, doing so reliably erases the deficit people are trying to create.
Terms explained
- MET
- Metabolic equivalent. One MET is resting energy use; a 7-MET activity uses seven times that rate.
- Kilocalorie
- What food labels call a calorie. One kcal is 1,000 physics calories, and the terms are used interchangeably in nutrition.
- BMR
- Basal metabolic rate: energy used at complete rest, keeping you alive. Typically the largest part of daily expenditure.
- TDEE
- Total daily energy expenditure — BMR plus movement, exercise and digestion. The number that matters for weight management.
- EPOC
- Excess post-exercise oxygen consumption: the modest extra burn after hard exercise. Real, and generally much smaller than fitness marketing suggests.
- NEAT
- Non-exercise activity thermogenesis — fidgeting, walking, standing, chores. Varies enormously between people and often exceeds deliberate exercise.
Common questions
- How accurate is this estimate?
- It is a population average built from MET tables, so it can be off by 20% or more for an individual. Age, fitness, body composition, terrain and technique all shift the real figure.
- Why does my weight change the result?
- Because moving more mass takes more energy. Weight enters the formula directly, so a 90 kg person burns roughly 30% more than a 70 kg person doing the same thing.
- Are the numbers on gym machines reliable?
- Usually optimistic. Machines that do not know your weight are estimating for an assumed person, and even those that do tend to run high.
- What is a MET?
- A metabolic equivalent — a multiple of your resting energy use. Walking briskly is about 4.3 METs, meaning it costs a little over four times what sitting does.
- Do I burn more calories in the cold?
- Slightly, if you are actually shivering or working to stay warm. In practice the effect is small and easily outweighed by moving more slowly.
- Does building muscle raise my metabolism much?
- Modestly. Muscle burns more at rest than fat does, but the difference per pound is small — the larger benefit is strength, function and what you can do in training.
- Should I eat back the calories I burn?
- Given that burn estimates run high and intake estimates run low, eating back the full figure often cancels the deficit entirely. Partial is the more cautious approach.
- Is exercise or diet more effective for weight loss?
- Diet, by a wide margin, because it is far easier to not eat 500 calories than to burn them. Exercise is where most of the health benefit lives, which is a different question.