Metabolic Age Calculator

Your metabolic age answers a simple question: if someone in the general population had your BMR, how old would they typically be? A 35-year-old with the BMR of a typical 28-year-old has a metabolic age of 28 — seven years younger than they look on paper.

This matters because BMR decline with age is not inevitable. Most age-related BMR loss is driven by muscle loss (sarcopenia), not time itself. People who maintain lean mass through resistance training routinely keep metabolic ages 10-15 years below their chronological age well into their 60s and beyond.

Why BMR Matters

• BMR accounts for 60-75% of the calories you burn in a day
• Every pound of muscle burns ~6 cal/day at rest; fat burns ~2
• Lean mass is the strongest single predictor of BMR
• Age-related metabolic slowdown is real but smaller than most people think

How to Lower Metabolic Age

• Lift weights: 2-4 sessions per week focused on compound movements
• Eat enough protein: 0.7-1 g per pound of bodyweight supports muscle retention
• Sleep 7-9 hours: muscle recovery and hormonal balance depend on it
• Stay active: NEAT (non-exercise activity) meaningfully raises total energy expenditure
• Manage body fat — excess fat crowds out lean tissue over decades