What is TDEE?

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a single day. It accounts for all energy used — from basic biological functions like breathing and circulation to physical activity such as walking, exercising, and even fidgeting. Understanding your TDEE is essential for managing body weight: eating above it leads to weight gain, eating below it leads to weight loss, and matching it maintains your current weight.

TDEE is calculated by first determining your Basal Metabolic Rate (BMR) — the energy your body needs at complete rest — and then multiplying it by an activity factor that reflects your daily movement level. The more active you are, the higher your TDEE.

What is BMR?

Basal Metabolic Rate (BMR) represents the minimum number of calories your body requires to sustain vital functions while at rest. This includes maintaining body temperature, organ function, cell production, and nutrient processing. BMR typically accounts for 60–75% of total daily calorie expenditure, making it the largest component of TDEE. Factors such as age, sex, weight, and height all influence BMR.

Tool description

This TDEE calculator estimates your Total Daily Energy Expenditure and Basal Metabolic Rate using the Mifflin-St Jeor equation. Enter your sex, age, weight, height, and activity level to receive personalized daily calorie estimates. The tool supports both metric and imperial unit systems and calculates results instantly in your browser.

How it works

The calculator uses the Mifflin-St Jeor equation, which is considered one of the most accurate BMR formulas for the general population:

  • Male: $BMR = 10 \times weight_{kg} + 6.25 \times height_{cm} - 5 \times age + 5$
  • Female: $BMR = 10 \times weight_{kg} + 6.25 \times height_{cm} - 5 \times age - 161$

The BMR is then multiplied by an activity factor to produce the TDEE:

Activity Level Multiplier Description
Sedentary 1.2 Little or no exercise, desk job
Lightly active 1.375 Light exercise 1–3 days per week
Moderately active 1.55 Moderate exercise 3–5 days per week
Active 1.725 Hard exercise 6–7 days per week
Very active 1.9 Intense daily exercise or physical job

Features

  • Calculates both BMR and TDEE with a single set of inputs
  • Uses the widely validated Mifflin-St Jeor equation
  • Five activity levels from sedentary to very active
  • Supports metric (kg/cm) and imperial (lb/ft/in) units
  • Instant client-side calculation with no data stored

Use cases

  • Understanding how changes in activity level affect your daily calorie usage

Options explained

  • Unit system: Toggle between metric and imperial measurements.
  • Sex: Biological sex (male or female), which affects the BMR formula constant.
  • Activity level: Your typical weekly exercise frequency and intensity, used to multiply BMR into TDEE.
  • Age: Your age in years. BMR decreases with age due to changing body composition.
  • Weight: Body weight in kilograms or pounds.
  • Height: Height in centimeters, or feet and inches in imperial mode.

FAQ

Which BMR formula is used? The Mifflin-St Jeor equation, published in 1990. It is recommended by the Academy of Nutrition and Dietetics as the most reliable formula for estimating BMR in healthy adults.

How accurate is the TDEE estimate? The Mifflin-St Jeor equation is accurate to within approximately 10% for most individuals. Actual energy expenditure varies based on genetics, body composition, hormonal factors, and specific activity patterns.