BMR Calculator
Calculate your Basal Metabolic Rate — the calories your body burns at complete rest. See results from three formulas, plus your TDEE at different activity levels.
Your results
What is BMR?
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions at complete rest — breathing, circulating blood, cell production, and maintaining body temperature. BMR accounts for 60–75% of your total daily calorie expenditure.
The Mifflin-St Jeor equation
The Mifflin-St Jeor equation, developed in 1990, is considered the most accurate BMR formula for the general population. For men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5. For women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161.
BMR vs TDEE
Your TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor ranging from 1.2 (sedentary) to 1.9 (very active). To lose weight, eat below your TDEE. To gain weight, eat above it. A deficit or surplus of 500 calories per day typically results in ~1 lb of weight change per week.
Related: Calorie Calculator · Macro Calculator · BMI Calculator
· Reviewed by the Vital Health Editorial Team
How This Calculator Works
This calculator uses the Mifflin-St Jeor equation, the current gold standard recommended by the Academy of Nutrition and Dietetics:
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
BMR represents the calories your body burns at complete rest to maintain vital functions (breathing, circulation, cell production). Total Daily Energy Expenditure (TDEE) is estimated by multiplying BMR by an activity factor: sedentary ×1.2, lightly active ×1.375, moderately active ×1.55, very active ×1.725, extra active ×1.9.
For informational purposes only — not medical advice. Consult a healthcare provider for personalized recommendations.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories you burn at complete rest — it accounts for about 60–75% of daily calorie burn. TDEE (Total Daily Energy Expenditure) adds activity calories on top of BMR. A sedentary person's TDEE is about 1.2× their BMR, while a very active person's is 1.725× or higher.
Why is the Mifflin-St Jeor equation better than Harris-Benedict?
The Mifflin-St Jeor equation (1990) was found to be more accurate than the older Harris-Benedict equations (1919 and 1984), particularly for overweight and obese individuals. The Harris-Benedict equation tends to overestimate BMR by about 5%. Most modern calculators and dietitians use Mifflin-St Jeor.
How accurate is the BMR calculator?
Formulas estimate BMR within about ±10% for most people. The most accurate method is indirect calorimetry (measuring oxygen consumption in a lab), but this is impractical for everyday use. Factors like muscle mass, genetics, hormones, and certain medications can cause individual variation.
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