BMR Calculator | Basal Metabolic Rate & Daily Calorie Needs

📖 How to Use This BMR Calculator

Choose your unit system - Select Metric (cm/kg) or Imperial (ft/in/lbs).

Enter your measurements - Height, weight, age, and select your gender.

Click "Calculate BMR & TDEE" - Get your BMR and daily calorie needs for different activity levels.

Use TDEE for weight management - Eat below TDEE to lose weight, above to gain weight.

📚 What is BMR (Basal Metabolic Rate)?

Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain basic vital functions like breathing, circulation, cell production, and temperature regulation. BMR accounts for approximately 60-75% of your total daily energy expenditure.

Knowing your BMR is the first step in calculating your Total Daily Energy Expenditure (TDEE), which helps with weight loss, weight gain, or weight maintenance goals.

🧮 Mifflin-St Jeor BMR Formula

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

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

🏃‍♂️ TDEE Activity Multipliers

Sedentary (1.2) - Little or no exercise, desk job
Lightly active (1.375) - Light exercise 1-3 days/week
Moderately active (1.55) - Moderate exercise 3-5 days/week
Very active (1.725) - Hard exercise 6-7 days/week
Super active (1.9) - Physical job + intense daily exercise/athlete

💡 How to Use BMR for Weight Management

To lose weight: Eat 300-500 calories below your TDEE daily
To maintain weight: Eat at your TDEE level
To gain weight: Eat 300-500 calories above your TDEE daily
Never eat below your BMR - Going below BMR can be unhealthy

❓ Frequently Asked Questions (FAQ)

What is the difference between BMR and RMR?

BMR (Basal Metabolic Rate) is measured under strict conditions (complete rest, after sleep, in a darkened room). RMR (Resting Metabolic Rate) is slightly higher and measured under less strict conditions. For practical purposes, they are very similar.

Which BMR formula is most accurate?

The Mifflin-St Jeor equation (used by this calculator) is considered the most accurate for the general population, followed by the Harris-Benedict equation revised by Mifflin and St Jeor in 1990.

Does muscle mass affect BMR?

Yes! Muscle tissue burns more calories at rest than fat tissue. Increasing muscle mass through strength training can raise your BMR by 5-10%, helping with long-term weight management.

Why does BMR decrease with age?

As we age, we naturally lose muscle mass (sarcopenia) and our metabolic rate slows. Regular exercise and strength training can help maintain a higher BMR as you get older.

Can I increase my BMR?

Yes! Building muscle through strength training, eating enough protein, staying hydrated, getting adequate sleep, and eating regular meals can help increase your metabolic rate naturally.

Is BMR the same for everyone with same stats?

No, BMR can vary between individuals with the same height, weight, age, and gender due to differences in muscle mass, body composition, genetics, and hormone levels.