Calculate Metabolic Rate

Estimate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).

Your Estimated Metabolic Rate

Basal Metabolic Rate (BMR):

Total Daily Energy Expenditure (TDEE):

Units: kcal/day

BMR is the calories your body burns at rest. TDEE is BMR multiplied by an activity factor.

Metabolic Rate Calculation Details

This calculator estimates your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).

BMR Formulas:

Mifflin-St Jeor Equation (most common):

• For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
• For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161

Harris-Benedict Equation (original):

• For Men: BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) – (6.755 × age in years)
• For Women: BMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) – (4.780 × age in years)

This calculator primarily uses the Mifflin-St Jeor equation for its accuracy.

TDEE Calculation:

TDEE = BMR × Activity Factor

The Activity Factor is a multiplier based on your reported daily activity level.

Metabolic Rate Variables

Variables Used in Metabolic Rate Calculation

Variable	Meaning	Unit	Typical Range
Gender	Biological sex, affects baseline metabolic rate.	Unitless (Male/Female)	Male, Female
Age	Years since birth, metabolism generally slows with age.	Years	1-120
Weight	Body mass.	kg or lb	1 – 600 (depending on unit)
Height	Body stature.	cm, in, or ft'in"	1 – 300 (depending on unit)
Activity Factor	Multiplier based on physical activity level.	Unitless	1.2 – 1.9
BMR	Basal Metabolic Rate: Energy expended at rest.	kcal/day	800 – 2500+
TDEE	Total Daily Energy Expenditure: Total calories burned daily.	kcal/day	1200 – 3500+

Metabolic Rate Calculator Examples

Here are a couple of examples to illustrate how the metabolic rate calculator works:

Example 1: Moderately Active Woman

Inputs:

• Gender: Female
• Age: 35 years
• Weight: 65 kg
• Height: 168 cm
• Activity Level: Moderately active (1.55)

Calculation:

• BMR (Mifflin-St Jeor): (10 × 65) + (6.25 × 168) – (5 × 35) – 161 = 650 + 1050 – 175 – 161 = 1364 kcal/day
• TDEE: 1364 kcal/day × 1.55 = 2114 kcal/day

Results:

• BMR: Approximately 1364 kcal/day
• TDEE: Approximately 2114 kcal/day

Example 2: Active Man (using pounds and inches)

Inputs:

• Gender: Male
• Age: 28 years
• Weight: 180 lb (approx. 81.65 kg)
• Height: 5′ 10″ (approx. 70 inches or 177.8 cm)
• Activity Level: Very active (1.725)

Calculation (using converted kg and cm):

• Weight Conversion: 180 lb / 2.20462 = 81.65 kg
• Height Conversion: 5'10" = (5 * 12 + 10) inches = 70 inches. 70 inches * 2.54 = 177.8 cm
• BMR (Mifflin-St Jeor): (10 × 81.65) + (6.25 × 177.8) – (5 × 28) + 5 = 816.5 + 1111.25 – 140 + 5 = 1792.75 kcal/day
• TDEE: 1792.75 kcal/day × 1.725 = 3092.7 kcal/day

Results:

• BMR: Approximately 1793 kcal/day
• TDEE: Approximately 3093 kcal/day

How to Use This Metabolic Rate Calculator

1. Select Gender: Choose 'Male' or 'Female' from the dropdown.
2. Enter Age: Input your age in years.
3. Enter Weight: Input your weight and select the unit (kg or lb).
4. Enter Height: Input your height and select the unit. If you choose 'Feet & Inches', two new input fields will appear for feet and inches respectively.
5. Select Activity Level: Choose the option that best describes your typical weekly physical activity.
6. Calculate: Click the 'Calculate' button.
7. Interpret Results: Your BMR and TDEE will be displayed in kilocalories per day (kcal/day).
8. Reset: Click 'Reset' to clear all fields and start over.
9. Copy Results: Click 'Copy Results' to copy the calculated BMR, TDEE, and units to your clipboard.

Unit Conversion: The calculator automatically handles conversions between kilograms/pounds and centimeters/inches to ensure accuracy, regardless of your input units.

Key Factors Affecting Metabolic Rate

• Body Composition: Muscle tissue burns more calories at rest than fat tissue. Higher muscle mass leads to a higher BMR.
• Age: Metabolism tends to slow down with age, partly due to a decrease in muscle mass and hormonal changes.
• Genetics: Individual genetic makeup plays a significant role in determining a person's basal metabolic rate. Some people naturally have faster metabolisms.
• Hormones: Thyroid hormones, in particular, play a crucial role in regulating metabolism. Imbalances can significantly alter metabolic rate.
• Environment: Exposure to extreme cold or heat can increase metabolic rate as the body works harder to maintain its core temperature.
• Physical Activity: While BMR accounts for resting metabolism, overall daily energy expenditure (TDEE) is heavily influenced by the amount and intensity of physical activity.
• Diet: Extreme calorie restriction can slow down metabolism as the body tries to conserve energy. Conversely, the thermic effect of food (TEF) means digestion itself burns calories.
• Body Size and Shape: Larger individuals generally have higher metabolic rates due to having more body mass to support.

Frequently Asked Questions (FAQ)

What is Basal Metabolic Rate (BMR)?

BMR is the minimum number of calories your body needs to perform essential life-sustaining functions at rest, such as breathing, circulation, and cell production. It's the energy your body would burn if you spent the entire day resting in a temperature-neutral environment.

What is Total Daily Energy Expenditure (TDEE)?

TDEE represents the total number of calories you burn in a 24-hour period, including your BMR, the thermic effect of food (digestion), and calories burned through physical activity (exercise and non-exercise activity thermogenesis – NEAT).

Which formula does this calculator use?

This calculator primarily uses the Mifflin-St Jeor equation, which is widely considered one of the most accurate formulas for estimating BMR across different populations.

How accurate are these metabolic rate calculations?

These formulas provide estimates. Actual metabolic rates can vary significantly due to genetics, body composition (muscle vs. fat), hormonal factors, and other individual differences. For precise measurements, clinical testing like indirect calorimetry may be required.

How does activity level affect TDEE?

The activity level multiplier significantly impacts TDEE. The more active you are, the higher the multiplier, and thus the higher your estimated daily calorie needs.

Can I use this calculator if I'm pregnant or breastfeeding?

No, these standard formulas are not accurate for pregnant or breastfeeding individuals, as their metabolic needs are significantly altered. Consult a healthcare professional for personalized advice.

What's the difference between kilograms and pounds, or centimeters and inches?

Kilograms (kg) and centimeters (cm) are part of the metric system, while pounds (lb) and inches (in) are part of the imperial system. The calculator handles conversions between these units automatically.

What does it mean if my TDEE is higher than my BMR?

It's expected! Your TDEE will always be higher than your BMR because TDEE includes the calories burned from all daily activities, not just resting functions.

Metabolic Rate Breakdown Chart