Weight Loss Calculator – Daily Calories, Time, Macros & Fat-Loss Planner
This Weight Loss Calculator brings four powerful tools into one page. It helps you estimate how many calories you should eat per day, how long it may take to reach your goal weight, how to split your macros, and how much fat you need to lose based on your body fat percentage.
Four Weight Loss Tools in One
- Daily Calorie Target: Uses your age, sex, height, weight, activity level and goal weight to estimate BMR, maintenance calories (TDEE) and a calorie target based on your desired speed of weight loss.
- Weight Loss Timeline: Starts from your daily calorie deficit and calculates how long it might take to reach your goal weight.
- Macro Planner: Converts your daily calorie target into grams of protein, carbs and fat using your preferred macro split.
- Body Fat Fat-Loss Calculator: Uses body fat percentage to estimate lean mass, goal weight at target body fat and how long it may take to get there.
Calorie and Weight Loss Assumptions
This calculator uses a common approximation that 1 kilogram of fat corresponds to roughly 7,700 calories of energy. Real-world results vary by individual, starting weight, body composition, hormones, adherence and other factors.
Formulas Used
BMR (Mifflin–St Jeor):
For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
For women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
TDEE: TDEE = BMR × activity factor
Calorie deficit for weight loss: deficit ≈ (weekly_weight_loss_kg × 7700) ÷ 7
How to Use This Weight Loss Calculator
- Start with the Daily Calorie Target tab to find a realistic daily calorie goal and time estimate.
- Use the Weight Loss Timeline tab if you already know your daily deficit and want a simple time forecast.
- Go to the Macro Planner tab to break your calories into protein, carbs and fat in grams.
- Use the Body Fat tab if you know your body fat percentage and want a fat-loss view of your journey.
This tool is for educational use only and does not replace professional medical or nutrition advice. Always consult a doctor or registered dietitian before starting any aggressive diet or weight loss program.