Project when you'll reach your goal weight using TDEE and a calorie deficit or surplus. Includes Mifflin-St Jeor BMR, activity multiplier, and a weight projection chart.
BMR (Mifflin-St Jeor) = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5 (male) or −161 (female)
TDEE = BMR × activity multiplier (1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extremely active). Weekly weight change = (TDEE − Daily calorie intake) × 7 ÷ 7,700 kg (using 7,700 kcal = 1 kg body mass). The timeline recalculates BMR at each projected weight milestone to model the slowing metabolism effect.
Worked example: 85kg male, 175cm, 35 years, moderately active. BMR = (10×85) + (6.25×175) − (5×35) + 5 = 850 + 1,093.75 − 175 + 5 = 1,774 kcal. TDEE = 1,774 × 1.55 = 2,749 kcal. Goal: 75kg. Deficit: 500 kcal/day → intake 2,249 kcal. Weekly loss ≈ 0.45 kg → 10kg lost in approximately 22 weeks (5.5 months), accounting for metabolic slowdown.