1. What is TDEE?

Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day, including basal metabolic rate (BMR) and activity. It's the most accurate way to determine your calorie needs for weight maintenance, loss, or gain.

2. Mifflin-St Jeor Equation

The calculator uses the Mifflin-St Jeor equation for BMR:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in centimeters
• \( age \) — Age in years
• \( s \) — +5 for males, -161 for females

TDEE Calculation: BMR is then multiplied by an activity factor to estimate total daily calorie expenditure.

3. Activity Factors

Activity Levels:

• 1.2 - Sedentary (little or no exercise)
• 1.375 - Lightly active (light exercise 1-3 days/week)
• 1.55 - Moderately active (moderate exercise 3-5 days/week)
• 1.725 - Very active (hard exercise 6-7 days/week)
• 1.9 - Extra active (very hard exercise & physical job)

4. Using the Calculator

Tips: Enter your weight in kg, height in cm, age in years, select gender and activity level. For accurate results, use recent measurements.

5. Frequently Asked Questions (FAQ)

Q1: Why use Mifflin-St Jeor instead of Harris-Benedict?
A: Mifflin-St Jeor is more accurate for modern populations, with error rates about 5% compared to 10-15% for Harris-Benedict.

Q2: How accurate is TDEE calculation?
A: For most people, within 10% of actual expenditure when using accurate inputs. Individual variations exist.

Q3: Should I use TDEE for weight loss?
A: Yes, subtract 250-500 kcal from TDEE for moderate weight loss (0.25-0.5 kg/week).

Q4: Does muscle mass affect BMR?
A: Yes, muscle burns more calories at rest than fat. The equation accounts for this through weight.

Q5: How often should I recalculate?
A: Recalculate after significant weight changes (±5 kg) or activity level changes.