TDEE Calculator

Formula

TDEE = BMR × Activity Multiplier. Multipliers: Sedentary 1.2, Lightly Active 1.375, Moderately Active 1.55, Very Active 1.725, Extra Active 1.9. Standard activity coefficients from the Mifflin-St Jeor and Harris-Benedict equations.

Components

BMR accounts for 60-70% of TDEE in most people. The Thermic Effect of Food (TEF) — energy burned digesting and absorbing nutrients — adds about 10%. Non-Exercise Activity Thermogenesis (NEAT) — fidgeting, standing, walking — and structured Exercise make up the remainder. NEAT is highly variable and often the largest discretionary contributor to daily expenditure.

Limitations

Activity multipliers are population averages; individual variation in NEAT can shift true TDEE by ±300 kcal/day. TEF varies by macronutrient composition (protein ~25%, carbs ~8%, fat ~3%). Adaptive thermogenesis — metabolic slowdown during prolonged caloric deficit — can reduce TDEE below predicted values. Use this as a starting estimate and adjust based on real-world weight trend over 2-4 weeks. Note: The BMR/TEF/NEAT/Exercise breakdown is estimated — TEF is ~10% of total energy; the activity multiplier's premium is split ~40% structured exercise / ~60% NEAT. These are industry-standard approximations, not derived from your specific inputs.

Sources

Mifflin MD et al. (1990). Harris JA, Benedict FG (1919). Levine JA, Endocrinology — NEAT review (2002).