BMR Calculator

Calculate your Basal Metabolic Rate, estimated daily calorie needs and metabolic classification using the Mifflin-St Jeor formula.

How the BMR Calculator Works

Enter Details

Enter your height, weight, age, gender and activity level using metric or imperial units.

Calculate BMR

Instantly calculate your Basal Metabolic Rate using the Mifflin-St Jeor formula.

Get Insights

See your estimated TDEE, calorie targets and personalized metabolic health tips.

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic, life-sustaining functions such as breathing, circulation, cell production and maintaining body temperature while at complete rest. It represents the minimum energy your body requires each day, even if you did nothing but lie in bed.

🔥 Baseline Energy

BMR represents the calories your body burns at complete rest, before any activity is added.

📊 Foundation for TDEE

BMR is multiplied by an activity factor to estimate your Total Daily Energy Expenditure (TDEE).

BMR Formula (Mifflin-St Jeor)

Men: BMR = 10W + 6.25H − 5A + 5 Women: BMR = 10W + 6.25H − 5A − 161

Where W is weight in kilograms, H is height in centimeters and A is age in years. This is the most widely recommended BMR equation used by dietitians and health professionals today.

Activity Level Multipliers

Activity Level Multiplier
Sedentary (little or no exercise) 1.2
Lightly Active (1-3 days/week) 1.375
Moderately Active (3-5 days/week) 1.55
Very Active (6-7 days/week) 1.725
Extremely Active (athlete/physical job) 1.9

BMR vs TDEE

Feature BMR TDEE
Definition Calories at rest Total daily calories burned
Includes Activity No Yes
Used For Baseline metabolism Calorie planning
Typical Value Lower Higher

Factors That Affect Your BMR

💪 Muscle mass increases calorie burn at rest.
📉 BMR naturally decreases with age.
⚖️ Higher body weight generally raises BMR.
🚻 Men typically have a higher BMR than women.
🧬 Genetics influence individual metabolic rate.
🌡️ Hormonal factors like thyroid function play a role.
😴 Poor sleep can negatively affect metabolism.
🥗 Extreme calorie restriction can lower BMR over time.

Tips to Support a Healthy Metabolism

🏋️ Build lean muscle through resistance training.
🥗 Eat adequate protein to support muscle maintenance.
💧 Stay well hydrated throughout the day.
😴 Prioritize 7-9 hours of quality sleep.
🚶 Stay active with regular movement, not just workouts.
📉 Avoid extreme or prolonged calorie restriction.
🧘 Manage chronic stress levels.
🩺 Get regular checkups to monitor thyroid and hormone health.

About the BMR Calculator

A BMR (Basal Metabolic Rate) Calculator estimates the number of calories your body burns at rest using your height, weight, age and gender. This calculator uses the Mifflin-St Jeor equation, considered the most accurate widely-used formula, and also estimates your Total Daily Energy Expenditure (TDEE) based on your activity level.

Whether you're planning a weight loss journey, aiming to build muscle or simply want to understand your daily calorie needs, this BMR Calculator gives you a reliable starting point for setting nutrition goals.

Why BMR Matters for Weight Management

Understanding your BMR is the first step toward effective calorie planning. Since BMR represents the calories your body needs at rest, any additional activity increases your total energy needs above this baseline. Knowing this number helps you set an accurate calorie target, whether your goal is weight loss, maintenance or muscle gain.

📉 Weight Loss

A moderate calorie deficit below your TDEE, typically 500 calories per day, supports gradual, sustainable weight loss.

📈 Muscle Gain

A moderate calorie surplus above your TDEE, combined with resistance training, supports lean muscle growth.

Disclaimer

This BMR Calculator provides an estimate based on the information you enter and the Mifflin-St Jeor formula. Individual metabolism can vary due to genetics, medical conditions and other factors. Please consult a qualified healthcare professional or registered dietitian for personalized nutrition advice.

Frequently Asked Questions

1. What is a BMR Calculator?

A BMR Calculator estimates the number of calories your body burns at complete rest based on your height, weight, age and gender.

2. How is BMR different from TDEE?

BMR is the calories burned at rest, while TDEE includes BMR plus calories burned through daily activity and exercise.

3. Which BMR formula does this calculator use?

This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula for most adults.

4. Can I use my BMR to lose weight?

Yes. By calculating your TDEE and creating a moderate calorie deficit, typically around 500 calories per day, you can support gradual weight loss.

5. Is this BMR Calculator free?

Yes. This calculator is completely free and works on desktop, tablet and mobile devices.

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