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Basal Metabolic Rate Calculator

Accurately estimate your Basal Metabolic Rate (BMR) with our scientifically-backed calculator. Discover the number of calories your body burns at rest and tailor your nutrition and fitness goals.

BMR Calculator

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Enter your details and click "Calculate BMR" to see your results.

What is Basal Metabolic Rate (BMR)?

Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic life-sustaining functions such as breathing, circulation, cell production, and maintaining body temperature. It represents the minimum amount of energy your body requires when at complete rest, fasting, and in a thermoneutral environment.

Your BMR accounts for approximately 60-75% of the total calories you burn each day. Understanding your BMR is crucial for effective weight management, as it provides a baseline for determining your daily calorie needs based on your activity level.

How BMR is Calculated

There are several formulas used to estimate BMR, each with varying degrees of accuracy. The most commonly used equations include:

Mifflin-St Jeor Equation (1990)

Male: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
Female: (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

Considered the most accurate equation for most people and is widely used by nutritionists and dietitians.

Harris-Benedict Equation (Revised 1984)

Male: 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) - (5.677 × age in years)
Female: 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)

An older equation that has been revised to improve accuracy but is slightly less accurate than the Mifflin-St Jeor equation.

Katch-McArdle Formula

BMR = 370 + (21.6 × Lean Body Mass in kg)
Lean Body Mass = Weight × (1 - (Body Fat Percentage / 100))

This formula is considered the most accurate for individuals who know their body fat percentage, as it takes into account lean body mass.

Our calculator uses the Mifflin-St Jeor equation by default, as it is widely regarded as the most accurate for general use. However, you can select other formulas based on your preference and available information.

Factors Affecting Your BMR

Several factors influence your Basal Metabolic Rate, including:

Body Composition

Muscle burns more calories at rest than fat, so individuals with more muscle mass have a higher BMR.

Body Size

Larger individuals with more body mass generally have higher BMRs because it takes more energy to maintain a larger body.

Gender

Males typically have higher BMRs than females due to higher muscle mass and lower body fat percentage on average.

Age

BMR decreases with age, primarily due to loss of muscle mass and a decrease in physical activity.

Hormonal Factors

Thyroid hormones play a key role in regulating metabolism. An overactive thyroid increases BMR, while an underactive thyroid decreases it.

Environmental Temperature

Extreme cold or heat can slightly increase BMR as the body works to maintain its core temperature.

Tips to Boost Your Metabolism

  • Engage in regular strength training to build muscle mass
  • Eat protein-rich foods, which require more energy to digest
  • Stay hydrated by drinking plenty of water throughout the day
  • Get enough sleep (7-9 hours per night) to support metabolic health
  • Incorporate high-intensity interval training (HIIT) into your routine
  • Consume spicy foods containing capsaicin to temporarily boost metabolism
  • Avoid crash diets, which can slow down your metabolism

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About BMR Calculations

While BMR calculators provide a good estimate of your basal metabolic rate, it's important to remember that they are based on averages and may not perfectly reflect your individual metabolism.

For the most accurate results, consider consulting with a healthcare professional or registered dietitian who can take into account additional factors such as medical history, body composition, and activity patterns.

Learn more about BMR

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