Step-by-Step Calculation
- Calculate BMR using the Mifflin-St Jeor equation with your weight, height, age, and sex.
- Choose an activity multiplier based on your typical weekly exercise (sedentary 1.2, lightly active 1.375, moderately active 1.55, very active 1.725).
- Multiply BMR by the activity multiplier to get TDEE.
Worked Example
A 30-year-old man, 80 kg, 180 cm tall, moderately active:
BMR = (10 × 80) + (6.25 × 180) − (5 × 30) + 5 = 800 + 1125 − 150 + 5 = 1,780 calories
TDEE = 1,780 × 1.55 ≈ 2,759 calories/day to maintain current weight. For weight loss, he'd target roughly 2,259 calories/day (a 500-calorie deficit).
Frequently Asked Questions
Is Mifflin-St Jeor the most accurate formula?
Among widely available formulas, it's considered one of the most accurate for the general population, generally outperforming the older Harris-Benedict equation in modern validation studies.
Should I eat back calories burned from exercise?
If you selected an activity multiplier that already accounts for your regular exercise, you generally shouldn't eat back those calories separately — that would effectively double-count them.
