Free online metabolic age calculator using BMR comparison with peer averages to estimate your body's metabolic age. Includes body fat and muscle mass adjustments. All calculations run locally. | No signup · Data never leaves your device
Zero Dependencies · Works OfflineFree online metabolic age calculator using BMR comparison with peer averages to estimate your body's metabolic age. Includes body fat and muscle mass adjustments. All calculations run locally.
Fitness Progress：Check monthly after starting a workout program to track whether strength training is actually raising your basal metabolic rate — more scientific than weight alone.
Plateau Diagnosis：If weight drops but metabolic age does not improve, you may be losing muscle instead of fat. Adjust protein intake and training approach.
Health Age Management：Use metabolic age as your body's real age indicator, motivating yourself to make your body younger than your ID through exercise and nutrition.
Metabolic age compares your actual Basal Metabolic Rate (BMR) to the average BMR of people your age. A metabolic age lower than your actual age means your metabolism is faster/younger; higher means it is slower and may need diet and exercise adjustments.
We first calculate your actual BMR using the Mifflin-St Jeor equation, then compare it to average BMR for your age, sex, and weight. If your BMR is above average, your metabolic age is younger than actual; if below, older. People with lower body fat and more muscle typically have higher BMR.
Building muscle is most effective — each kg of muscle adds ~13-20 calories to daily BMR. Strength training, adequate protein (1.6-2.0g per kg bodyweight), and sufficient sleep (7-9 hours) all help lower metabolic age.
A gap of plus or minus 3 years is normal. Over 5 years suggests lifestyle review. But this is an estimate, not a replacement for comprehensive health checkups.
Body composition matters. At 70kg, someone with 30kg muscle mass may burn 100-200 more calories/day than someone with 25kg muscle. Muscle is metabolically active tissue; fat has a much lower metabolic rate.