What this calculator does
This tool estimates the energy you expend (in kilocalories, kcal) during a daily-life activity or a workout. It uses the activity's intensity expressed in METs (Metabolic Equivalent of Task), your body weight, and how long you do the activity. One MET equals the energy cost of sitting quietly at rest, so an activity rated at 4 METs burns roughly four times as much energy per minute as resting.
The METs values offered here come from Japan's Ministry of Health, Labour and Welfare "Physical Activity Standards for Health Promotion 2013," which derives from the international Compendium of Physical Activities. The calorie formula and METs concept are universal and used worldwide, so the tool works for anyone, anywhere.
How to use it
Choose an activity type, pick an activity from the dropdown (or type a custom METs value to override it), enter the duration in minutes, and enter your body weight in kilograms. The result shows the selected METs intensity and the estimated calories burned.
The formula explained
The calculation is: $$\text{kcal} = \text{METs} \times \text{weight(kg)} \times \text{hours} \times 1.05$$. Duration is entered in minutes, so it is converted to hours by dividing by 60. The 1.05 factor represents roughly 1.05 kcal burned per kilogram of body weight per MET-hour. This is mathematically equivalent to the common international form, \(\text{METs} \times 3.5 \times \text{weight} \times \text{minutes} \div 200\).
Worked example
Suppose you take a normal-paced walk (3 METs) for 60 minutes and weigh 60 kg. Hours = \(60 / 60 = 1\). Calories = $$3 \times 60 \times 1 \times 1.05 = 189 \text{ kcal}$$ 189 kcal.
FAQ
Does this include resting metabolism? Yes. METs is a total figure, not "extra" burn. To estimate only the additional calories above rest, use \((\text{METs} - 1)\) in place of METs.
How accurate is it? It is an estimate. Actual expenditure varies with fitness, terrain, efficiency, and individual metabolism, so treat the number as a useful approximation.
What if my activity is not listed? Enter a custom METs value, which you can look up in the Compendium of Physical Activities for almost any task.
