A calories burned calculator estimates the energy an activity uses from its MET value, your body weight and how long you do it. Formula: kcal = METs x weight kg x (minutes / 60). Headline rounds to whole kcal. A 70 kg person exercising at 7 METs for 45 minutes burns about 368 kcal.
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How to use the calories burned calculator
- Enter your weight in kilograms.
- Enter the duration in minutes.
- Enter the activity’s MET value.
- Read the estimated calories burned.
What is the calories burned formula?
- Calories burned = MET × body weight (kg) × time (hours)
- 1 MET is roughly the energy you use sitting quietly, about 1 kcal per kg per hour
- Weight in kg = pounds ÷ 2.2046
A MET (metabolic equivalent of task) expresses how hard an activity is compared with rest. An activity of 7 METs uses about seven times the energy of sitting still. The calories burned calculator multiplies that intensity by your weight and the duration.
Calories burned calculator worked example
A 70 kg person exercising for 45 minutes at 7 METs burns 7 × 70 × 0.75 = about 368 kcal. The same person working out for 30 minutes at different intensities:
| METs | Intensity | kcal in 30 min (70 kg) |
|---|---|---|
| 2.5 | Light | 88 |
| 3.5 | Moderate | 123 |
| 5.0 | Moderate | 175 |
| 7.0 | Vigorous | 245 |
| 10.0 | Vigorous | 350 |
Light, moderate and vigorous
The Physical Activity Guidelines for Americans, 2nd edition, from the U.S. Department of Health and Human Services, define light activity as under 3.0 METs, moderate as 3.0 to 5.9 METs and vigorous as 6.0 METs or more. Brisk walking is a typical moderate activity; running and fast cycling are typically vigorous. If you do not know an activity’s MET value, these bands give a reasonable range to enter in the calories burned calculator.
How much activity adults need
- 150 to 300 minutes a week of moderate activity, or 75 to 150 minutes of vigorous activity, or an equivalent mix.
- Muscle-strengthening activity for all major muscle groups on 2 or more days a week.
- More activity brings additional benefits, and some activity is better than none.
How accurate is the estimate?
MET values are averages measured in groups of people. Your actual burn depends on fitness, body composition, technique, terrain and temperature, so two people of the same weight can differ noticeably. The formula also counts the energy you would have used at rest anyway; to see only the extra calories from exercise, subtract 1 MET (use 6 instead of 7). Fitness trackers estimate from heart rate and movement and also carry error. Treat any number as a rough guide rather than a precise count.
Exercise and weight management
Exercise burns fewer calories than many people expect: about 368 kcal for 45 minutes of vigorous effort can be replaced by a single snack. Activity has large health benefits regardless of weight, but for weight loss it works best alongside changes in diet. This calories burned calculator provides general information, not medical advice; talk to your doctor before starting vigorous exercise if you have a heart condition or other health concerns.
Putting the numbers to work
To compare two workouts, run the calories burned calculator twice. Walking for 60 minutes at a moderate 3.5 METs burns about 245 kcal for a 70 kg person, while 30 minutes of vigorous exercise at 7 METs burns the same 245 kcal in half the time. Both count toward the weekly guidelines: under the HHS guidelines, one minute of vigorous activity counts roughly the same as two minutes of moderate activity, so 75 vigorous minutes are equivalent to 150 moderate ones.
Body weight matters because moving a heavier body takes more energy. At 7 METs for 45 minutes, a 55 kg person burns about 289 kcal and a 95 kg person about 499 kcal. If you track your weight over time, update it in the calories burned calculator so the estimates stay realistic. Spreading activity across the week, rather than cramming it into one session, also lowers the risk of injury, and building up gradually helps your body adapt.
Related converters and calculators
Related calculators:
- Calorie calculator: daily calories
- TDEE calculator: energy use
- BMR calculator: resting energy
- Pace calculator: running pace
Sources
HHS: Physical Activity Guidelines for Americans, 2nd edition.
Questions about this calculator
What is a MET?
A multiple of resting energy use; 1 MET is sitting quietly.
How many calories does 45 minutes at 7 METs burn?
About 368 kcal for a 70 kg person.
What counts as vigorous activity?
6.0 METs or more, per HHS.
How much exercise do adults need?
150–300 min moderate or 75–150 min vigorous a week, plus strength work 2 days.
Are fitness tracker numbers more accurate?
They are also estimates and carry error.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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