What is BMR (Basal Metabolic Rate)?

BMR (Basal Metabolic Rate) is the minimum amount of energy your body needs to function at rest, accounting for 60-75% of total daily energy expenditure. It covers essential functions like breathing, circulation, cell production, and temperature regulation.

What's the difference between BMR and TDEE?

BMR is the calories your body burns at complete rest just to stay alive. TDEE (Total Daily Energy Expenditure) includes BMR plus all physical activities, exercise, and the thermic effect of food. TDEE = BMR × activity factor. For weight loss, eat between BMR and TDEE.

How can I use BMR for weight loss?

To lose weight, consume calories between your BMR and TDEE, creating a 300-500 calorie deficit. Never eat below your BMR as it slows metabolism and causes muscle loss. Combine cardio and strength training, eat adequate protein, and aim for 0.5-1 kg (1-2 lbs) loss per week.

Which formula is more accurate: Mifflin-St Jeor or Harris-Benedict?

Mifflin-St Jeor is generally considered more accurate as it was developed with a more modern population and has smaller error margins. The Harris-Benedict equation (1984 revision) may slightly overestimate BMR in some populations. This calculator provides both for comparison.

What factors affect basal metabolic rate?

Factors affecting BMR include: age (decreases 1-2% per decade after 20), gender (men typically 5-10% higher), muscle mass (more muscle = higher BMR), body size, genetics, thyroid function, ambient temperature, and dieting history. Building muscle is the most effective way to increase BMR naturally.

Does BMR change with age?

Yes, BMR gradually declines with age, typically 1-2% per decade after age 20, primarily due to muscle loss and hormonal changes. This explains why weight gain becomes easier with age. Regular strength training and adequate protein intake can help slow this decline.

Free Online BMR Calculator - Basal Metabolic Rate

📊 Enter Your Data

♂ Male

♀ Female

Age (years)

Height (cm)

Weight (kg)

📋 Results

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BMR (calories/day)

Mifflin-St Jeor Equation

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BMR (calories/day)

Harris-Benedict Equation

🏃 Total Daily Energy Expenditure (TDEE)

🎯 Weight Management Goals

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Maintain Weight (cal/day)

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Weight Loss (cal/day)

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Muscle Gain (cal/day)

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Daily Protein (grams)

📐 Mifflin-St Jeor Equation

Male: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5

Female: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161

📐 Harris-Benedict Equation (1984 Revised)

Male: BMR = 88.362 + 13.397 × weight(kg) + 4.799 × height(cm) - 5.677 × age

Female: BMR = 447.593 + 9.247 × weight(kg) + 3.098 × height(cm) - 4.330 × age

❓ About BMR

Basal Metabolic Rate (BMR) is the minimum energy required to sustain life at complete rest. Understanding your BMR is the first step toward scientific weight management.

Why BMR Matters

Accounts for 60-75% of total daily energy expenditure
Foundation for science-based weight loss—never eat below BMR
Essential for muscle gain—eat above TDEE for muscle growth
Helps understand your metabolic type

Factors Affecting BMR

Muscle Mass: Each kg of muscle increases BMR by 13-30 cal/day
Age: Decreases 1-2% per decade after age 20
Gender: Men typically have 5-10% higher BMR than women
Genetics: Some people naturally have faster metabolism
Hormones: Thyroid function directly affects metabolic rate

⚠️ Results are estimates. Actual BMR varies by individual. Consult a registered dietitian or physician for personalized advice.

🔥 BMR Calculator

How to Use the 🔥 BMR Calculator