How to Calculate TDEE
TDEE is calculated in two steps: first determine your BMR (calories burned at rest), then multiply by an activity factor.
Step 1: Calculate BMR (Mifflin-St Jeor)
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161
Step 2: Apply Activity Multiplier
- Sedentary (desk job, little exercise): BMR × 1.2
- Lightly active (1-3 days/week exercise): BMR × 1.375
- Moderately active (3-5 days/week): BMR × 1.55
- Very active (6-7 days/week): BMR × 1.725
- Extremely active (athlete, physical job + training): BMR × 1.9
BMR Formula Comparison
This calculator compares three BMR formulas side-by-side:
Mifflin-St Jeor (1990)
Considered the most accurate for the general population. Uses weight, height, age, and sex. This is the primary formula used for TDEE calculation in the results above.
Harris-Benedict (1919, revised 1984)
The original BMR equation. Men: 88.362 + (13.397 × weight kg) + (4.799 × height cm) - (5.677 × age). Women: 447.593 + (9.247 × weight kg) + (3.098 × height cm) - (4.330 × age). Tends to overestimate calorie needs by about 5% compared to Mifflin-St Jeor.
Katch-McArdle
Uses lean body mass instead of total weight: BMR = 370 + (21.6 × lean mass kg). Requires knowing your body fat percentage. Most accurate for people with significantly above-average or below-average muscle mass. Enter your body fat % in the calculator to see this formula's result.
Macro Breakdown Explained
The calculator provides a protein/carbs/fat breakdown for each calorie target:
- Protein: 2g per kg body weight (capped at 40% of total calories). Higher protein intake supports muscle retention during weight loss and muscle building during a surplus
- Fat: 25% of total calories. Essential for hormone production, vitamin absorption, and cell function. Going below 20% can impair hormonal health
- Carbs: Fills the remaining calories. Primary fuel source for high-intensity exercise and brain function
These are general starting points. Athletes, ketogenic dieters, and people with specific medical conditions may need different ratios.
Using TDEE for Your Goals
Weight Loss
Eat 500 calories below TDEE for approximately 1 pound of fat loss per week. A 250-calorie deficit produces about 0.5 lb/week. Aggressive deficits (1000+ calories) risk muscle loss and metabolic adaptation.
Weight Maintenance
Eat approximately your TDEE. A range of ±100 calories is perfectly fine for maintaining weight.
Muscle Gain
Eat 250-500 calories above TDEE (a "lean bulk"). Combined with resistance training and adequate protein (0.7-1g per lb bodyweight), this supports muscle growth while minimizing fat gain.
Goal Timeline
The goal timeline feature estimates how long it takes to reach a weight target at a 500 calorie/day deficit or surplus. This assumes a steady rate of ~1 lb per week (3,500 calories = 1 lb of fat). In practice, weight loss slows over time as your body adapts and your TDEE decreases with lower body weight. Recalculate your TDEE every 10-15 lbs lost for more accurate planning.
Hidden Calorie Burns: NEAT and TEF
Your TDEE includes more than just exercise:
- NEAT (Non-Exercise Activity Thermogenesis): Calories burned through fidgeting, walking, standing, and daily tasks. NEAT can vary by 500-2,000 calories/day between individuals. People who move more throughout the day — even without formal exercise — burn significantly more
- TEF (Thermic Effect of Food): Your body burns calories digesting food. Protein costs 20-30% of its calories to digest, carbs 5-10%, and fat 0-3%. This is one reason high-protein diets support fat loss
For a complete fitness assessment, combine TDEE with our BMI Calculator and Body Fat Calculator.