MET Calculator – Metabolic Equivalent Calorie Estimator

A Metabolic Equivalent of Task (MET) is a ratio that compares the energy cost of an activity to the energy cost of quiet sitting. A value of 1.0 MET represents resting energy expenditure — approximately 3.5 mL of oxygen consumed per kilogram of body weight per minute.

When an activity has a MET value of 5.0, it means the body uses roughly 5 times the energy it would at rest. MET values are catalogued in the Compendium of Physical Activities, a research reference maintained since 1993 and updated most recently in 2024.

The standard MET calorie equation is:

Calories = (MET × 3.5 × Weight_kg × Duration_min) / 200

This formula derives from the relationship between oxygen consumption and energy expenditure. The constant 3.5 represents resting O₂ uptake in mL/kg/min, and 200 is the conversion factor from mL O₂ to kilocalories (approximately 5 kcal per liter of O₂, adjusted for the units used).

The result is an estimate. Actual energy expenditure varies with fitness level, technique, environmental conditions, and individual metabolism.

The Compendium and major physical activity guidelines classify activities by MET value into three intensity tiers:

MET-minutes are calculated by multiplying the MET value by the duration in minutes. This metric is commonly used in research to quantify total activity volume independent of body weight.

For context, major physical activity references often cite a weekly target of 500–1000 MET-minutes for general fitness. For example, 150 minutes of moderate walking (3.5 METs) yields 525 MET-minutes per week.

Many workouts combine different activities — for example, a warm-up walk followed by jogging and then stretching. The session builder lets you add each segment with its own MET value and duration, then view the combined total.

This approach provides a more accurate session estimate than using a single average MET value, because higher-intensity segments contribute proportionally more to total expenditure.

MET values represent population averages from controlled studies. Individual variation can be significant due to differences in fitness, body composition, movement efficiency, and environmental factors such as temperature, altitude, or terrain.

The standard formula assumes a resting O₂ consumption of 3.5 mL/kg/min, which may not be accurate for everyone. This tool provides informational estimates for personal tracking and journaling purposes.