The formula
kcal per minute = METs × 3.5 × weight ÷ 200
Where it comes from
One MET is the cost of sitting still: 3.5 millilitres of oxygen per kilo per minute. Every activity has a measured cost in METs — running is 9.8, nearly ten times resting — and since a litre of oxygen consumed is worth about five kilocalories, the formula follows. That is also why the figure is proportional to weight: moving a ninety-kilo body costs more than moving a sixty-kilo one.
How to work it out by hand
- Look up the METs of the activity: running at a middling pace is 9.8
- Multiply by 3.5 and by your weight in kilos
- Divide by 200: that is the kilocalories per minute
- Multiply by the minutes of the session
What is worth knowing
The table values are population averages from the Compendium of Physical Activities, the reference used by studies and by fitness apps alike. A given person's real cost can be twenty per cent either side depending on their efficiency, their muscle mass and even the temperature. One warning about the figure in grams of fat: it comes from dividing by the 7,700 kcal stored in a kilo of fat tissue, so it is a theoretical equivalence and not a promise of weight loss. The body does not spend only what the gym machine says.