Calorie Calculator: Daily Calorie Target for Fat Loss, Maintenance or Muscle Gain with a Goal Timeline
Free online daily calorie target calculator. It combines your Mifflin–St Jeor BMR, activity-factor TDEE and a lose/maintain/gain goal with a weekly rate to give your daily calorie intake, your deficit or surplus, and an estimated time to reach a healthy weight. Results update live and can be saved to local history, with all calculations running privately in your browser.
Your details & goal
Set daily intake from BMR × activity (TDEE)
Daily calorie target
Fat-loss deficit / maintain / muscle surplus
At this rate, about 14 weeks to reach a healthy BMI range (rough estimate).
How to Use
Calorie Target & Deficit Guide
TDEE deficit/surplus · goal timeline
The calorie target calculator uses your sex, height, weight, age and activity to compute BMR via Mifflin–St Jeor, multiplies it by an activity factor to get TDEE, then quantifies your daily intake target based on whether you want to lose, maintain or gain weight and your chosen weekly rate. One kg of body fat holds about 7700 kcal, so losing 0.5 kg/week needs a daily deficit of about 550 kcal. It also estimates the weeks to reach a healthy BMI range, giving you an actionable plan.
01 Setting a science-based deficit
Fat loss is fundamentally negative energy balance: intake < expenditure. Larger deficits produce faster loss but cost muscle, lower metabolism, and can cause gallstones and nutrient deficiencies. Mainstream guidelines suggest 300–750 kcal/day (≈0.25–0.75 kg/week) — a sustainable pace that preserves muscle.
Muscle gain needs about 250–500 kcal/day above TDEE along with resistance training. Too large a surplus mainly adds fat; natural trainees can build only about 0.25–0.5 kg of muscle per month (more for beginners).
- 1 kg body fat ≈ 7700 kcal
- 0.25 kg/week ≈ −275 kcal/day
- 0.5 kg/week ≈ −550 kcal/day
- 0.75 kg/week ≈ −825 kcal/day
- Intake should not stay below BMR; women generally ≥1200, men ≥1500 kcal/day
02 Tracking and adjusting
Log food and morning weight for 2 weeks. If weight moves at the expected rate, the target works; if it stalls, cut 100–200 kcal or add activity. Daily weight swings from water, salt and the menstrual cycle are normal — look at the 7-day average, not single days. Recompute every 3–5 kg lost because BMR/TDEE fall.
Inputs
- sexSelects the BMR formula constants.
- ageYour age in years.
- height / weightBody measurements used to compute BMR and TDEE.
- activityActivity factor applied to BMR to get TDEE.
- goalLose, maintain or gain weight.
- weekly rateHow fast to lose/gain; sets the daily deficit or surplus.
Actions
- CalculateBMR, TDEE, target intake and timeline update live as you type; this button saves the result to the history drawer.
- ResetRestores the default inputs.
- Favor nutrient-dense foods so you get more protein, vitamins and fiber for the same calories
- Eat 1.6–2.2 g of protein per kg body weight, or 2.0–2.4 g/kg while cutting
- Poor sleep and stress raise cortisol, increasing hunger and hindering fat loss
- Do not eliminate an entire macronutrient; too little fat disrupts hormone production
- At a plateau, first check logging accuracy, then make small adjustments instead of drastic cuts
Wondering how many calories to eat per day to lose weight, maintain or gain muscle? This calculator derives BMR and TDEE from sex, height, weight, age and activity, then applies your goal (lose/maintain/gain) and a weekly rate to give your daily target calories, energy deficit or surplus, and estimated time to goal. Metric or imperial.
Energy balance: the core of weight change
Weight changes with the gap between calories in and out. Eating below TDEE creates a deficit and weight loss; eating above it creates a surplus and gain. One kg of body fat ≈ 7700 kcal, so losing 0.5 kg/week needs about a 550 kcal daily deficit and gaining 0.25 kg/week about a 275 kcal daily surplus.
How TDEE is calculated
The tool first computes BMR with the Mifflin–St Jeor equation, then multiplies by an activity factor: sedentary ×1.2, light ×1.375, moderate ×1.55, very active ×1.725 and extra active ×1.9. Choosing the right activity level matters a lot — most office workers are sedentary to lightly active.
A sensible rate of loss or gain
A safe rate is about 0.3–0.75 kg lost per week (300–750 kcal daily deficit); faster loss risks muscle loss, metabolic slowdown and rebound. Do not eat below BMR — generally at least 1200 kcal/day for women and 1500 for men. For muscle gain, 0.25–0.5 kg/week is a reasonable surplus.
Turning calories into food
Once you have a daily target, use the Macronutrient calculator to split it into grams of protein, carbs and fat, and the Water calculator for hydration. A lower calorie target is not always better — adequate protein and resistance training help preserve muscle during a deficit.
FAQ
QHow many calories should I eat to lose weight?
A daily deficit of 300–750 kcal below TDEE is safe — about 0.3–0.75 kg/week. Do not drop below BMR; women generally need at least 1200 kcal/day and men at least 1500.
QHow much weight can a 500-calorie deficit lose in a month?
500 × 30 = 15,000 kcal ÷ 7700 ≈ 1.95 kg, about 2 kg. Real results vary with water weight and metabolic adaptation.
QWhy ask for age and sex?
BMR depends on both. Men usually have more muscle and a higher BMR, and metabolism declines with age — the Mifflin–St Jeor equation accounts for both.
QWhich activity factor should I choose?
Sedentary 1.2 for a desk job; 1.375 for 1–3 light days; 1.55 for 3–5 moderate days; 1.725 for 6–7 hard days; 1.9 for a physical job or twice-daily training.
QHow big a surplus do I need to build muscle?
Usually 200–400 kcal/day (0.25–0.5 kg/week); a larger surplus mostly adds fat. Beginners and lighter trainees may use a bit more, paired with consistent resistance training and enough protein.