Formula: Mifflin-St Jeor Equation
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
TDEE = BMR × Activity Factor
Frequently Asked Questions
What is BMR?
BMR (Basal Metabolic Rate) is the number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production while at complete rest. It accounts for 60-75% of total daily calorie expenditure.
What formula does this calculator use?
This calculator uses the Mifflin-St Jeor equation, considered the most accurate for most people. Men: BMR = 10×weight + 6.25×height − 5×age + 5. Women: BMR = 10×weight + 6.25×height − 5×age − 161.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. It represents total calories burned in a day including physical activity. Activity factors range from 1.2 (sedentary) to 1.9 (very active).
How do I use BMR for weight loss?
To lose weight, eat fewer calories than your TDEE. A deficit of 500 calories/day typically leads to about 1 pound of weight loss per week. Never eat below your BMR for extended periods.
Does BMR decrease with age?
Yes, BMR typically decreases by about 1-2% per decade after age 20, mainly due to loss of muscle mass. Strength training can help maintain a higher BMR as you age.
Can I increase my BMR?
Yes. Building muscle through strength training increases BMR since muscle burns more calories at rest than fat. Eating enough protein, staying hydrated, and adequate sleep also support healthy metabolism.
Why is my BMR different from my friend's?
BMR varies based on height, weight, age, gender, and body composition. Taller, heavier people generally have higher BMRs. Men typically have higher BMRs than women due to more muscle mass.
Is the Mifflin-St Jeor equation accurate?
It's considered the most accurate BMR formula for most populations. However, it may underestimate BMR for very muscular individuals and overestimate for very overweight individuals. Indirect calorimetry is the gold standard.