Select an activity, enter duration and body weight to estimate calories burned.
How it works
MET-based calorie estimate
Calories burned = (Time × MET × Weight) ÷ 200. MET (Metabolic Equivalent of a Task) measures how intense an activity is relative to sitting at rest (MET 1). Running has a MET of ~10, meaning it burns 10× more calories than resting.
The number of calories the body burns during daily activities or exercise depends on many variables, so no calculator can give a perfectly exact figure. The results here are estimates based on standardised data referencing an average person. The formula and methodology are described in the sections below.
Generally, calories consumed minus calories burned through activity and basal metabolic rate (BMR) determines whether a person maintains, loses, or gains weight. If the difference is zero, weight stays the same. A negative difference leads to weight loss; a positive difference leads to weight gain. Use our BMR calculator to find your resting calorie baseline.
Factors Affecting Calories Burned
Most estimates — including this calculator — rely on three key factors: body mass, duration of activity, and the Metabolic Equivalent of a Task (MET). Here is how each one works:
Body Mass and Duration
A heavier person burns more calories even at rest because the body must do more work to sustain itself. During exercise, a person weighing 90 kg will burn significantly more calories performing the same activity for the same duration as someone weighing 60 kg. Duration has a direct relationship with calories burned — the longer the activity, the more calories are used — but intensity also matters. Walking for one hour burns far fewer calories than running for the same hour.
Exercise Intensity and MET
Exercise intensity is the most nuanced factor. It can be measured by heart rate or, more precisely, by oxygen consumption. Oxygen consumption and exercise intensity have a linear relationship — as intensity increases, oxygen demand increases proportionally.
This is where MET (Metabolic Equivalent of a Task) comes in. MET is the ratio of energy expended during an activity relative to energy expended at rest. By convention, 1 MET equals the energy used by an average person sitting quietly — roughly 3.5 mL of oxygen per kilogram per minute, derived from a healthy 40-year-old male weighing 70 kg. An activity with a MET of 4 requires four times the energy of sitting still.
Intensity Level
MET Range
Example
Light
1.0 – 2.9
Slow walking, cooking, stretching
Moderate
3.0 – 5.9
Brisk walking, cycling leisure, dancing
Vigorous
6.0+
Running, jump rope, martial arts
Fat Burning and Intensity
Exercise intensity also determines which fuel source the body uses. At lower intensities, the body relies more on fat for energy. As intensity increases, it shifts toward carbohydrates. This means that for fat loss specifically, longer sessions at lower intensity can be more effective than short high-intensity bursts — though total calorie deficit over time is ultimately what drives fat loss.
Other Contributing Factors
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Age
Older individuals tend to have less lean muscle mass, which lowers resting metabolic activity and reduces total calories burned.
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Body Composition
Muscle tissue burns more calories than fat tissue at rest. Two people of the same weight can have very different calorie burn rates depending on their muscle-to-fat ratio.
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Temperature
Warmer environments raise body temperature, allowing the body to direct more energy toward calorie burn rather than warming itself.
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Fitness Level
A fitter person's body is more efficient and uses less energy to perform the same task, meaning they burn fewer calories than a less fit person doing the same exercise.
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Diet
Diet affects metabolism. A diet that supports a higher metabolic rate will result in more calories burned throughout the day.
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Sleep
Poor sleep increases fatigue, reduces exercise output, and can lower metabolism — all of which reduce total daily calorie burn.
How Calories Burned is Calculated
This calculator uses the following MET-based formula:
Formula
Calories = (Time × MET × Body Weight) ÷ 200
Time is in minutes · Body weight is in kilograms
Worked Example
A person weighing 70 kg runs at moderate pace (MET 9.8) for 30 minutes:
The accuracy of this estimate is significantly affected by MET values, which were derived from a single reference subject — a healthy 40-year-old male weighing 70 kg. Studies have shown that the conventional 1 MET value can overestimate oxygen consumption at rest by 20–30% on average for people who differ from this profile.
Additionally, MET values assume the activity is performed continuously at a constant rate. In practice, activities like tennis or basketball involve rest periods, which means the actual duration of effort is shorter than the total session time — leading to an overestimate of calories burned. Use these results as a directional guide rather than a precise measurement.
Key takeaway
MET values are most useful as an index of relative intensity — they tell you how demanding one activity is compared to another. For precise individual calorie measurement, lab-based testing with oxygen consumption analysis is required.