What is metabolic age?

Metabolic age compares your basal metabolic rate (BMR) to the average BMR for different ages in the population. If your BMR matches that of a younger average person, your metabolic age is lower than your real age. It is an estimate popularised by body-composition scales, not a clinical measurement.

How is it calculated?

We compute your BMR with the Mifflin-St Jeor equation, then find the age whose average reference BMR is closest to yours. A higher BMR generally maps to a younger metabolic age.

Is anything uploaded?

No. All calculations happen locally in your browser.

Metabolic Age Calculator

Metabolic age calculator

Metabolic age estimates how your basal metabolic rate (BMR) — the energy your body burns at rest — compares to population averages, then reports the age whose average BMR matches yours.

A metabolic age lower than your real age suggests a relatively high resting metabolism, often associated with more muscle mass and good fitness. A higher metabolic age suggests the opposite.

This tool calculates your BMR with the Mifflin-St Jeor equation (the most accurate widely-used predictive formula) and compares it to a same-sex reference. It is an informational estimate, not a clinical measure — and runs entirely in your browser.