BMR Calculator
Basal Metabolic Rate calculation. Mifflin-St Jeor equation with gender, age, height, weight.
Free · Runs in your browser · No signup
Mifflin–St Jeor estimate. Not medical advice.
Examples to try
Mifflin-St Jeor
Men: 10w + 6.25h − 5a + 5 · Women: 10w + 6.25h − 5a − 161 (w kg, h cm, a years).
Common mistakes
- Using BMR as daily food target (you still need activity calories).
- Mixing cm/inches or kg/lb without conversion.
- Expecting one number to fit athletes or clinical conditions perfectly.
Scope: Resting calorie estimate for education. For daily needs, use the calorie calculator.
How to Use
Enter your values in the fields above and click Calculate to get instant results. Calculations run in your browser. Results are estimates for personal planning only.
Related Calculators
How BMR Is Calculated
CalcSolver's BMR calculator uses the Mifflin-St Jeor equation — the formula recommended by the Academy of Nutrition and Dietetics as the most accurate for most people.
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
The result is calories burned at complete rest. Multiply by an activity factor (1.2–1.9) to get your Total Daily Energy Expenditure (TDEE).
BMR Reference Factors
Sedentary (little/no exercise): BMR × 1.2
Lightly active (1–3 days/week): BMR × 1.375
Moderately active (3–5 days/week): BMR × 1.55
Very active (6–7 days/week): BMR × 1.725
Extra active (physical job + training): BMR × 1.9
BMR drops roughly 2% per decade after age 20. Building lean muscle through resistance training raises your BMR permanently.
Basal Metabolic Rate Explained
Your BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to maintain vital functions like breathing, circulation, and cell production. CalcSolver's BMR calculator uses the Mifflin-St Jeor equation: Men: (10 × weight) + (6.25 × height) − (5 × age) + 5; Women: (10 × weight) + (6.25 × height) − (5 × age) − 161.
A 30-year-old woman, 165cm, 60kg has a BMR of approximately 1,319 calories/day. With moderate activity (1.55 multiplier), her total daily needs are about 2,044 calories. About 60-75% of daily calorie expenditure comes from BMR — making it the largest factor in your energy needs.
BMR decreases with age (about 2% per decade after 20) and with muscle loss. Building muscle through resistance training permanently increases your BMR, making weight management easier long-term. Calculate your full energy needs using CalcSolver's calorie calculator and check your weight status with the BMI calculator.
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Frequently Asked Questions
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain basic life functions like breathing, circulation, and cell production. It represents the minimum energy your body needs.
What formula does this calculator use?
This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate for estimating BMR: For men: 10×weight(kg) + 6.25×height(cm) – 5×age – 161. For women: 10×weight(kg) + 6.25×height(cm) – 5×age + 5.
How is BMR different from TDEE?
BMR is your calorie burn at rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor. A sedentary person has TDEE of about 1.2×BMR, while an active person might be 1.725×BMR.
Can I increase my BMR?
Yes. Building muscle mass is the most effective way to increase BMR, as muscle tissue burns more calories at rest than fat. Regular strength training, adequate protein intake, and sufficient sleep all help maintain a higher BMR.