TDEE Calculator

Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a 24-hour period, encompassing all energy used for basal metabolism, physical activity, and food digestion. TDEE is the single most important number in nutrition planning because it determines your maintenance calorie level — the intake at which your weight remains stable. Eating above TDEE leads to weight gain; eating below leads to weight loss. Without knowing your TDEE, any diet plan is essentially guessing.

TDEE is composed of three main components. Basal Metabolic Rate (BMR) is the largest component at 60-75%, representing the energy needed for vital organ function, cellular processes, and temperature regulation at complete rest. The Thermic Effect of Activity (TEA) accounts for 15-30% and includes all physical movement from structured exercise to fidgeting and walking. The Thermic Effect of Food (TEF) comprises about 10%, representing the metabolic cost of digesting, absorbing, and processing nutrients.

This TDEE Calculator uses the Mifflin-St Jeor equation for BMR estimation, widely regarded as the most accurate for healthy adults, multiplied by an activity factor that accounts for your typical daily physical activity level. The activity factors used are based on the Harris-Benedict activity level system: Sedentary (1.2), Lightly Active (1.375), Moderately Active (1.55), Very Active (1.725), and Extra Active (1.9). These multipliers were derived from doubly labeled water studies that directly measured total energy expenditure in free-living individuals.

Beyond your maintenance TDEE, the calculator provides a mild cut and lean bulk recommendation. A 15% deficit (mild cut) creates approximately a 300-500 kcal daily deficit depending on your TDEE, suitable for gradual fat loss while preserving muscle mass. A 15% surplus (lean bulk) provides the additional energy needed for muscle protein synthesis during a resistance training program while minimizing unnecessary fat gain. These moderate adjustments are more sustainable than aggressive deficits or surpluses.

Accurate TDEE estimation requires honest assessment of your activity level, which is the most common source of error. Most people overestimate their activity level, leading to inflated TDEE estimates and stalled weight loss. When in doubt, choose a lower activity level and adjust based on real-world results over 2-3 weeks. Monitor your weight trend (weekly averages, not daily fluctuations) to verify whether your estimated TDEE matches reality.