What a MET Value Actually Measures (It's Not Calories)

A ratio, not a calorie figure

MET stands for Metabolic Equivalent of Task, and despite showing up on every "calories burned" chart, a MET value itself contains no calorie information at all — it's a ratio describing how many times more energy an activity uses compared to sitting quietly at rest, which is defined as exactly 1 MET.

Why body weight has to enter the calculation

Because MET is a multiple of resting metabolism, and resting metabolism itself scales with body size, the same activity at the same MET value burns more absolute calories for a heavier person than a lighter one — which is exactly why the calorie formula multiplies MET by body weight, not just duration.

The formula

Calories = MET × Body Weight (kg) × Duration (hours). A MET of 8 for 30 minutes isn't "X calories" on its own — it only becomes a calorie figure once your specific body weight is factored in.

Where the numbers come from

MET values for hundreds of activities — from sitting to sprinting — are published in the Compendium of Physical Activities, a standardized reference developed and periodically updated by exercise physiologists specifically so researchers and calculators use consistent numbers rather than everyone guessing independently.

Why it's still an estimate

Published MET values are averages across many people under standardized conditions — your actual energy use varies with fitness level, efficiency of movement, terrain, and effort, so a MET-based estimate is a solid ballpark, not a metabolic lab reading.

Estimate yours

Our Calories Burned Calculator applies standard MET values across twenty common activities to your own body weight and duration.