Metabolic Age Calculator
Compare your basal metabolic rate against demographic population averages
Chronological age: 35 | Delta: -17 years
Mathematical Formula & Scientific Methodology
Formula: Inverse BMR Demographic Comparison Model
Estimated Age = (10W + 6.25H + S - Assessed BMR) / 5Solves the standard Mifflin-St Jeor equation inversely for the age variable corresponding to demographic median BMR.
Model Assumptions
- Adult demographic population median equations
Variables & Standard Units
| Symbol | Physiological Meaning | Unit |
|---|---|---|
| W | Weight in kg | dimensionless |
| H | Height in cm | dimensionless |
| S | Sex constant (+5 male, -161 female) | dimensionless |
Scientific Limitations
- Model-based population estimate only. Not an actual measurement of biological aging, cellular senescence, or clinical longevity.
Peer-Reviewed Scientific Citations
A new predictive equation for resting energy expenditure in healthy individuals (1990)
Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO (1990) — The American Journal of Clinical Nutrition, 51(2), 241-247
Key Finding: Mifflin-St Jeor equation is accurate within ±10% of measured REE in non-obese and obese individuals, recommended by the Academy of Nutrition and Dietetics as the most reliable standard equation.
Frequently Asked Questions
Related Calculators & Next Steps
BMR Calculator
Calculate Basal Metabolic Rate using the gold-standard Mifflin-St Jeor equation
Resting Metabolic Rate Calculator
Calculate resting metabolic rate (RMR) with optional Cunningham lean mass calibration
FFMI Calculator
Fat-Free Mass Index & Normalized Natural Muscularity Potential