Nutrition

🔥 BMR Calculator (Basal Metabolic Rate)

Your Basal Metabolic Rate is the number of calories your body needs to perform basic, life-sustaining functions like breathing, circulation and cell production while at complete rest. This calculator uses the medically recognised Mifflin-St Jeor equation.

How the BMR Calculator Works

Your Basal Metabolic Rate is the number of calories your body needs to perform basic, life-sustaining functions like breathing, circulation and cell production while at complete rest. This calculator uses the medically recognised Mifflin-St Jeor equation. This calculator draws on peer-reviewed, industry-standard formulas used by fitness professionals, dietitians and clinicians worldwide, translated into a fast, easy-to-use browser tool.

Privacy first: All calculations happen instantly in your browser. HydraFit never transmits, stores, or shares any values you enter here.

Why This Matters For Your Health

Tracking metrics like this over time — rather than relying on a single reading — gives you a much clearer picture of trends in your health and fitness journey. Use this tool regularly alongside our other calculators for a fuller picture of your overall wellbeing.

Medical Disclaimer: This tool is for general educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. Read our full Medical Disclaimer.

Frequently Asked Questions

What is BMR used for?

BMR is the foundation for calculating your total daily calorie needs (TDEE) once activity level is factored in. It helps with building accurate weight loss, maintenance, or muscle gain plans.

Which formula does this calculator use?

We use the Mifflin-St Jeor equation, widely regarded by dietitians as more accurate than the older Harris-Benedict formula.

Why does BMR differ between men and women?

Men typically carry more lean muscle mass, which burns more calories at rest than fat tissue, resulting in a generally higher BMR.

Does BMR decrease with age?

Yes. BMR naturally declines with age due to gradual loss of muscle mass, which is why calorie needs typically decrease as we get older.

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