Harris-Benedict Calculator

How to Calculate TDEE & BMR Using the Harris-Benedict Equation

The Harris-Benedict equation is a widely used method for estimating an individual's Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE). This calculation is essential for understanding your body's energy needs and can be useful for weight management, fitness planning, and overall health assessment.

Harris-Benedict Formula

The Harris-Benedict equation consists of two main steps:

1. Calculate Basal Metabolic Rate (BMR):
   • For males: $$BMR = 88.362 + (13.397 * weight) + (4.799 * height) - (5.677 * age)$$
   • For females: $$BMR = 447.593 + (9.247 * weight) + (3.098 * height) - (4.330 * age)$$
2. Calculate Total Daily Energy Expenditure (TDEE): $$TDEE = BMR * Activity Factor$$

Where:

• Weight is in kilograms
• Height is in centimeters
• Age is in years
• Activity Factor ranges from 1.2 (sedentary) to 1.9 (very active)

Calculation Steps

1. Input your personal data: age, sex, height, weight, and activity level.
2. Calculate BMR using the appropriate formula based on sex.
3. Multiply BMR by the activity factor to get TDEE.

Example Calculation

Let's calculate the BMR and TDEE for a 30-year-old male who is 180 cm tall, weighs 75 kg, and has a moderately active lifestyle.

Step 1: Calculate BMR

$$\begin{align} BMR &= 88.362 + (13.397 * 75) + (4.799 * 180) - (5.677 * 30) \\ &= 88.362 + 1004.775 + 863.82 - 170.31 \\ &= 1786.647 \text{ calories/day} \end{align}$$

Step 2: Calculate TDEE (moderately active = 1.55)

$$\begin{align} TDEE &= 1786.647 * 1.55 \\ &= 2769.303 \text{ calories/day} \end{align}$$

Therefore, this person's estimated BMR is 1787 calories/day, and their TDEE is 2769 calories/day.

Visual Representation

This pie chart illustrates the breakdown of Total Daily Energy Expenditure (TDEE) into Basal Metabolic Rate (BMR) and Activity Energy Expenditure. BMR represents the calories burned at rest, while Activity Energy Expenditure accounts for the additional calories burned through daily activities and exercise.