BMR & TDEE Explained

BMR and TDEE are the foundation of any calorie-based plan. Understanding them is the difference between guessing and actually controlling your body composition.

Activity Multipliers

Activity LevelMultiplierDescription
Sedentary1.2Desk job, little/no exercise
Lightly active1.375Light exercise 1-3 days/week
Moderately active1.55Moderate exercise 3-5 days/week
Very active1.725Hard exercise 6-7 days/week
Extra active1.9Physical job + hard daily training

Mifflin-St Jeor Formula

  • Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
  • Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
  • Then TDEE = BMR × activity multiplier.

How to Use TDEE

  1. Calculate TDEE with the appropriate activity multiplier (start conservative).
  2. Track weight daily, average weekly.
  3. After 2-3 weeks, adjust based on actual change.
  4. Fat loss: 300-500 kcal below TDEE. Muscle gain: 200-300 above.

Try It Yourself

Calculate your maintenance calories with FitCalc's calorie calculator.

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Frequently Asked Questions

Calories burned at complete rest. 60-75% of total daily expenditure.
BMR × activity multiplier. Your maintenance calorie number.
Mifflin-St Jeor for general population; Katch-McArdle if you know body fat %.
Rough estimates. Most people overestimate — start low and adjust.
For maintenance yes; 10-25% below for loss, 5-15% above for gain.