About this tool
This calculator has two parts. First it estimates your daily energy needs with the Mifflin-St Jeor equation, then it maps a chosen deficit onto a realistic weight-loss timeline. All maths runs locally in your browser — nothing you type leaves your device.
Maintenance calories (TDEE) come from BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + (5 for male, −161 for female), multiplied by an activity factor from 1.2 (sedentary) to 1.9 (very active). For the timeline, roughly 7,700 kcal is burned per kilogram of fat (3,500 kcal per pound). Choosing 'by daily deficit' gives weeks-to-goal = (weight change × kcal per unit) ÷ (deficit × 7) and a projected date; choosing 'by goal date' works backwards to the daily deficit you would need. Your target daily intake is simply maintenance minus that deficit, and all date maths uses UTC day counts so daylight-saving shifts never move a date.
This is general educational information, not medical or dietary advice. The tool warns if your target intake drops below about 1,200 kcal (women) or 1,500 kcal (men), levels that are widely considered too low without supervision — always consult a qualified professional before starting a diet.