Calculate Your Biological Age: Longevity Markers You Should Know at 40

Want to age backwards? This page helps you:

• Differentiate biological and chronological age.
• Track your Basal Metabolic Rate (BMR) as a longevity marker.
• Take actionable steps to improve cellular health.

Explain Your Inputs: Why We Need This Data

To analyze your metabolic baseline, we need:

• Age & Gender: Metabolic rates naturally decline mathematically over time.
• Height & Weight: Essential for determining your mass-to-energy expenditure ratio.

Interpretation Guide: Actionable Context

What your BMR says about your aging process:

• A higher BMR relative to your peers: Often indicates a higher percentage of lean muscle mass. Muscle is metabolically expensive and highly correlated with longevity and lower biological age.
• If your BMR is dropping: Prioritize resistance training to build muscle density and combat sarcopenia.

Explainable Logic: The Math Behind the Tool

We calculate your resting energy expenditure using the Mifflin-St Jeor equation. The Formula: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + s Tracking this number provides a window into your mitochondrial health over time.

People Also Ask (PAA)

What is a good biological age? A good biological age is one that is lower than your chronological age. This indicates that your cells function like someone younger, often due to healthy lifestyle habits.

Does building muscle slow aging? Yes. Maintaining and building muscle mass through resistance training improves insulin sensitivity, increases BMR, and prevents age-related functional decline (sarcopenia).

How accurate is the Mifflin-St Jeor equation? It is currently considered the most accurate BMR formula for the general population by clinical dietitians, replacing older models like the Harris-Benedict equation.

Expand Your Health Suite

• Body Fat Calculator — Ensure your weight is healthy lean mass.
• Calorie Calculator — Adjust intake based on your BMR.

Pro Tip: Thanks to our Calculation Cards feature, your results are saved to your profile history. You can safely navigate to our other guides without losing your context!