BMR Calculator
Basal Metabolic Rate — calories your body burns at complete rest
About the BMR Calculator
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production. It represents your body's minimum daily energy requirement and forms the foundation for calculating your total daily calorie needs. Knowing your BMR helps you set realistic calorie targets for weight loss, maintenance, or muscle gain.
How to Use
- Select your gender and enter your age in years
- Enter your weight and height (choose kg/lbs and cm/inches)
- Choose a formula — Mifflin-St Jeor is recommended for most people
- Click Calculate BMR to see your result and activity-adjusted calorie levels
Formula Used
Men: 10W + 6.25H − 5A + 5
Women: 10W + 6.25H − 5A − 161
Harris-Benedict (revised):
Men: 88.36 + 13.4W + 4.8H − 5.68A
Katch-McArdle:
BMR = 370 + 21.6 × LBM
W = weight (kg), H = height (cm), A = age (years), LBM = Lean Body Mass (kg)
Understanding Your Results
Frequently Asked Questions
What is BMR vs TDEE?
BMR is the calories your body burns at complete rest just keeping organs running. TDEE = BMR × an activity multiplier — the calories you actually burn including movement, exercise and digestion. TDEE is what you use to plan a diet; BMR is the floor below which you should never eat.
How does age affect BMR?
BMR drops about 1–2% per decade after age 20, mainly due to gradual muscle loss. By age 70 it's typically 10–15% lower than at 25. Resistance training and protein intake slow this decline considerably.
Why is male BMR higher than female BMR?
Men typically carry 10–15% more lean muscle mass, which is metabolically active. The Mifflin-St Jeor formula (used here) reflects this with a +5 vs −161 sex constant.
Can I increase my BMR?
Yes, modestly. Strength training builds muscle, which raises BMR by ~10–15 kcal per kg of muscle gained. Adequate sleep, protein intake, and avoiding crash diets (which lower BMR via metabolic adaptation) all help.
Medical Disclaimer
This calculator provides estimates for general informational purposes only. Results are not a substitute for professional medical advice. Consult a qualified healthcare provider for personalised guidance.