TDEE Calculator — Total Daily Energy Expenditure by Activity Level

TDEE (Total Daily Energy Expenditure) is the total calories your body burns in a day, including at rest and during all activity. It's the baseline for any nutrition plan: to lose weight, eat below TDEE; to maintain, eat at TDEE; to gain muscle, eat above TDEE. Without knowing your TDEE, any calorie target is just a guess.

BMR (Basal Metabolic Rate) is the calories burned at complete rest — just keeping organs functioning, breathing, and maintaining body temperature. TDEE is BMR multiplied by an activity factor to account for all movement throughout the day. For a sedentary person, TDEE ≈ BMR × 1.2. For a very active person, TDEE ≈ BMR × 1.725. Most people's TDEE is 20–70% higher than their BMR.

TDEE estimates using the Mifflin-St Jeor formula are accurate within approximately 10–15% for most adults. The biggest source of error is the activity multiplier — choosing incorrectly is more impactful than any formula inaccuracy. The best approach: use the calculator as a starting point, then calibrate based on 2–3 weeks of consistent eating at the calculated level and actual weight change.

Yes — TDEE decreases during sustained caloric restriction through three mechanisms: reduced body mass (less tissue to maintain), reduced NEAT (you move less unconsciously when calorie-deprived), and adaptive thermogenesis (metabolic slowdown as a survival response). After 8–12 weeks of dieting, TDEE may be 10–20% lower than the formula predicts. This is the physiological basis of weight loss plateaus.

Create a 500-calorie daily deficit below your TDEE. If your TDEE is 2,400 calories, eat 1,900 calories/day to lose approximately 1 lb/week. Never go below 1,200 calories (women) or 1,500 calories (men) without medical supervision. Combine the deficit with adequate protein (0.7–1g per pound of body weight) and resistance training to preserve muscle during fat loss.

You can, but it depends on your approach. If you used the 'sedentary' multiplier and plan to track exercise separately, adding 50–75% of estimated exercise burn is reasonable (fitness trackers typically overestimate by 20–40%). If you used a multiplier that already accounts for your exercise frequency (moderately/very active), don't add extra calories on workout days — they're already baked into your TDEE. Consistency is more important than daily fine-tuning.