What Is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns just to keep you alive while at complete rest — breathing, circulating blood, regulating temperature, and maintaining organ function. It represents your body’s minimum energy requirement and typically accounts for 60–75% of total daily calorie expenditure.
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation (1990), which is considered the most accurate BMR formula for most people by the Academy of Nutrition and Dietetics:
Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
What Affects BMR?
BMR is influenced by age (decreases ~2% per decade after 20), sex (men typically have higher BMR due to more muscle mass), body composition (more muscle = higher BMR), and genetics. Extreme caloric restriction can lower BMR by up to 15–20% as the body adapts to conserve energy.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to account for your actual daily movement and exercise.
Can I increase my BMR?
Yes. Building muscle mass is the most effective long-term strategy, as muscle tissue burns more calories at rest than fat tissue. Resistance training 3–4 times per week consistently increases BMR over time.
How accurate is the Mifflin-St Jeor formula?
For most sedentary adults, it is accurate within 10%. It tends to overestimate BMR for very obese individuals and may underestimate it for lean, muscular athletes.
Medical Disclaimer: This calculator is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for health decisions.