How this instrument works
A MET, or metabolic equivalent of task, is a standardized way of expressing how energy-intensive an activity is: 1 MET is roughly the energy your body uses at rest, and an activity rated at 8 METs burns energy at about eight times your resting rate while you're doing it. Sitting quietly is close to 1 MET, brisk walking sits around 3 to 4 METs, and something like running or vigorous cycling can reach 8 METs or higher.
This calculator applies the standard formula behind most MET-based calorie estimators: kcal = MET x body weight in kilograms x duration in hours. It's a population-level estimate rather than a personalized one — it scales directly with body weight and time, but unlike some other energy-expenditure formulas it doesn't separately account for age, sex, or individual fitness, so treat the result as a solid ballpark rather than a lab-measured figure.
MET values for hundreds of specific activities, from vacuuming to competitive rowing, come from the Compendium of Physical Activities, a research reference periodically updated by exercise scientists including Barbara Ainsworth and colleagues. Looking up your specific activity's MET value there, rather than guessing, is what makes the rest of this calculation meaningful.
- Enter MET value of the activity — look up your specific activity in a MET reference table, or use a close match if yours isn't listed exactly.
- Enter Body weight in kilograms — convert from pounds first if needed (divide pounds by 2.2046).
- Enter Duration in hours — for a 45-minute session, enter 0.75; for 20 minutes, enter about 0.33.
- Read Calories burned in kcal — the estimated energy expenditure for that activity, weight and duration.
- For a multi-activity day, run the calculator once per activity and add the results together rather than averaging the MET values.
Worked example — MET 8 for a 70 kg person, 1 hour
Enter a MET value of 8 (a vigorous activity like running or a hard cycling session), a body weight of 70 kg, and a duration of 1 hour. The calculation is 8 x 70 x 1 = 560 kcal burned for that hour of activity.
Halve the duration to 30 minutes (0.5 hours) with everything else unchanged and the estimate scales linearly to 280 kcal — the formula treats duration and MET value as direct multipliers, so cutting the session in half cuts the estimated calorie burn in half too.
Questions
What exactly is a MET, and why does the formula use it?
MET stands for metabolic equivalent of task, a standardized unit where 1 MET approximates your resting energy expenditure. Using METs lets the same simple formula estimate calorie burn across wildly different activities — walking, swimming, gardening, competitive sport — because each activity's relative intensity has already been measured and assigned a MET value by exercise scientists, rather than needing a separate formula per activity.
Where do I find the MET value for my specific activity?
The Compendium of Physical Activities is the standard research reference, cataloguing MET values for hundreds of named activities from light housework to competitive rowing. If your exact activity isn't listed, pick the closest match by intensity and mechanics — a specific brand of home cardio machine won't be listed by name, but 'stationary cycling, moderate effort' likely will be.
Does this calculation account for my age, sex or fitness level?
No — the standard MET formula scales purely with the activity's MET value, your body weight, and time, without a separate adjustment for age, sex or fitness. Two people of the same weight doing the same activity for the same duration get the same estimate here, even though real individual energy expenditure varies somewhat with those other factors.
My duration is in minutes — how do I convert it to hours?
Divide the number of minutes by 60. Thirty minutes becomes 0.5 hours, forty-five minutes becomes 0.75 hours, and twenty minutes becomes roughly 0.33 hours. Entering minutes directly into the hours field will inflate the estimate by a factor of 60, so this conversion step matters.
How is this different from the MET-minutes-per-week calculator on this site?
They use the same MET values but answer different questions. This calculator converts a single activity into an estimated calorie count in kcal. The MET-minutes-per-week calculator instead sums MET x minutes across up to three weekly activities to produce a MET-minutes total for comparing against public-health physical-activity guidelines — it never converts to calories at all.