BMR Calculator

Calculate your Basal Metabolic Rate to understand how many calories your body needs at rest. Essential for weight management and fitness planning.

Calculate Your BMR

Your Basal Metabolic Rate

0 calories

This is the number of calories your body needs to perform basic life-sustaining functions at complete rest.

How to Calculate BMR

Understand the science behind Basal Metabolic Rate and how to use it for your health goals

1

Enter Your Details

Provide your gender, age, weight, and height. These factors significantly influence your metabolic rate.

2

Calculate Your BMR

Our calculator uses the Mifflin-St Jeor Equation, the most accurate formula for BMR calculation.

3

Use Your Results

Your BMR helps determine your daily calorie needs for weight maintenance, loss, or gain.

The Mifflin-St Jeor Equation

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

This equation is considered the most accurate for calculating BMR in healthy individuals. It accounts for the differences in metabolism between men and women.

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Why Use Our BMR Calculator?

Our calculator provides accurate, reliable results with these key benefits

Highly Accurate

Uses the scientifically validated Mifflin-St Jeor Equation for precise BMR calculation.

Personalized Results

Calculations are tailored to your specific gender, age, weight, and height.

Privacy Focused

All calculations happen locally in your browser. We never store your personal data.

Mobile Friendly

Access our calculator on any device with a seamless experience.

Completely Free

No hidden costs, subscriptions, or premium tiers. Always free to use.

Educational Resources

Learn how to use your BMR results effectively for your health goals.

Frequently Asked Questions

Get answers to common questions about BMR and metabolism

What is Basal Metabolic Rate (BMR)?

Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions while at complete rest. These functions include breathing, circulation, cell production, nutrient processing, protein synthesis, and ion transport. Essentially, it's the number of calories you would burn if you stayed in bed all day.

How is BMR different from TDEE?

BMR (Basal Metabolic Rate) represents the calories needed for basic bodily functions at complete rest. TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through daily activities and exercise. To calculate TDEE, you multiply your BMR by an activity factor (sedentary: 1.2, light activity: 1.375, moderate: 1.55, very active: 1.725, extra active: 1.9).

Why is BMR important for weight management?

Knowing your BMR helps you understand your baseline calorie needs. To lose weight, you need to consume fewer calories than your TDEE (which is based on your BMR). To gain weight, you need to consume more. A safe weight loss goal is typically creating a deficit of 500-1000 calories per day from your TDEE, resulting in 1-2 pounds of weight loss per week.

Can I change my BMR?

Yes, you can influence your BMR through several factors:

  • Muscle mass: Building muscle through strength training increases BMR as muscle tissue burns more calories at rest than fat tissue.
  • Age: BMR typically decreases with age as muscle mass tends to decrease.
  • Diet: Severe calorie restriction can lower BMR as your body adapts to conserve energy.
  • Hormones: Thyroid hormones significantly impact metabolic rate.

How accurate is the Mifflin-St Jeor Equation?

The Mifflin-St Jeor Equation is considered the most accurate BMR formula for the general population, with an accuracy of about ±10%. It's more reliable than the older Harris-Benedict Equation. However, individual variations in body composition, genetics, and health conditions can affect actual BMR. For the most precise measurement, clinical methods like indirect calorimetry are used.

Ready to Optimize Your Health?

Use our BMR calculator as the foundation for your fitness and nutrition plan