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BMR Calculator

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production while completely at rest. BMR typically accounts for 60-75% of your total daily calorie expenditure and is influenced by your age, sex, height, and weight.

Quick Answer

Average BMR is 1,200–1,600 calories/day for women and 1,400–2,000 for men. BMR is the calories your body burns at complete rest.

These results are estimates based on general formulas and are not a substitute for professional medical advice. Consult a healthcare provider before making health decisions.

Enter your details above to calculate your BMR.

Methodology & Sources

Reviewed and updated March 28, 2026 · Prepared by GetHealthyCalculators Editorial Team

This calculator uses the Mifflin-St Jeor equation, one of the most commonly recommended predictive equations for resting energy expenditure in healthy adults. Results are estimates and should be used as a planning baseline rather than an exact metabolic measurement.

References

  • A new predictive equation for resting energy expenditure in healthy individuals · American Journal of Clinical Nutrition
  • Nutrition and Athletic Performance · Academy of Nutrition and Dietetics, Dietitians of Canada, and ACSM

How the Formula Works

  1. Measure your weight in kilograms. If using pounds, convert by multiplying by 0.453592.

    weight (kg) = weight (lbs) × 0.453592

  2. Measure your height in centimeters. If using feet and inches, convert to centimeters first.

    height (cm) = (feet × 12 + inches) × 2.54

  3. Apply the Mifflin-St Jeor equation for males.

    BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

  4. Or apply the Mifflin-St Jeor equation for females.

    BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

  5. The result is your estimated BMR in calories per day — the energy your body uses at complete rest.

Limitations

  • The Mifflin-St Jeor equation estimates BMR and may not reflect your exact metabolic rate, which can only be measured precisely through indirect calorimetry.
  • BMR does not account for individual differences in body composition — two people of the same weight, height, age, and sex may have different BMRs depending on their muscle-to-fat ratio.
  • Certain medical conditions, medications, and hormonal imbalances can significantly alter metabolic rate beyond what the equation predicts.
  • BMR naturally decreases with age and may change during periods of caloric restriction, illness, or significant stress.
  • This tool is designed for adults and may not provide accurate results for children, adolescents, or pregnant/nursing women.

Frequently Asked Questions

What is BMR and why does it matter?
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain basic physiological functions such as breathing, blood circulation, and cell repair. It matters because BMR accounts for the largest portion of your daily calorie expenditure and serves as the foundation for calculating your total calorie needs.
What is the difference between BMR and TDEE?
BMR measures only the calories burned at rest, while TDEE (Total Daily Energy Expenditure) includes BMR plus the calories burned through physical activity, exercise, and the thermic effect of food. TDEE is your BMR multiplied by an activity factor.
How accurate is the Mifflin-St Jeor equation?
The Mifflin-St Jeor equation is considered one of the most accurate predictive formulas for estimating BMR in healthy adults. Research shows it is accurate within about 10% for most people, though individual variation exists due to differences in body composition and genetics.
Can I eat only my BMR calories to lose weight?
Eating at or below your BMR is generally not recommended for sustained periods, as it may not provide enough energy for daily activities and can lead to muscle loss, nutrient deficiencies, and metabolic adaptation. For weight loss, it is safer to eat between your BMR and TDEE.
How can I increase my BMR?
The most effective way to increase your BMR is to build lean muscle mass through resistance training, since muscle tissue burns more calories at rest than fat tissue. Staying well-hydrated, getting adequate sleep, and eating enough protein can also support a healthy metabolic rate.
Does BMR decrease with age?
Yes. BMR tends to decline with age because people often lose lean mass and become less active over time. That decline is one reason calorie needs often fall gradually as adults get older.
Can dieting lower my BMR?
Extended calorie restriction can reduce energy expenditure over time, especially if it causes muscle loss. Preserving lean mass with resistance training and adequate protein helps limit that drop.

Add your activity level to find your total daily calorie burn

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