Calorie Calculator

It uses the Mifflin-St Jeor equation — BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5 for men, or −161 for women — which is widely considered one of the more accurate BMR formulas in modern nutrition research, more so than older formulas like Harris-Benedict.

BMR (Basal Metabolic Rate) is the energy your body burns at complete rest just to keep you alive; TDEE (Total Daily Energy Expenditure, shown as Maintenance Calories) multiplies BMR by an activity multiplier from 1.2 to 1.9 to estimate your total calories burned including movement and exercise.

The tool subtracts 500 calories from your maintenance number for Mild Weight Loss and adds 500 for Mild Weight Gain — a 500-calorie daily deficit or surplus roughly corresponds to about one pound of body weight change per week, based on the commonly cited 3,500-calorie-per-pound estimate.

It's a population-level formula, so it's a solid starting estimate but individual metabolism varies based on muscle mass, genetics, hormones, and other factors — this is not medical advice, and anyone with a health condition should consult a doctor or dietitian before making major dietary changes.

Pick the option that best matches your typical week: Sedentary means little to no exercise, Lightly or Moderately active covers 1-5 days of exercise weekly, Very active means daily or near-daily exercise, and Extremely active is for people combining a physically demanding job with regular training.

Choose a goal from the dropdown — fast, moderate, or mild weight loss, maintenance, or mild or moderate weight gain — and the calculator applies a daily calorie adjustment (from -1000 to +500 kcal) to your maintenance calories, then shows the exact resulting weekly rate of weight change in both kilograms and pounds, calculated from the standard estimate of 3,500 kcal per pound (about 7,700 kcal per kilogram) of body weight.

Pick a diet style — Balanced, Higher Protein, Lower Carb, or Higher Carb — and the calculator splits your target calories into percentages for each macronutrient, then converts those calories to grams using the standard Atwater factors: 4 calories per gram of protein, 4 calories per gram of carbohydrate, and 9 calories per gram of fat.

If your goal calories fall below commonly cited safe minimums — about 1,500 kcal/day for men and 1,200 kcal/day for women — the calculator shows a warning, since very low-calorie diets can risk nutrient deficiencies and muscle loss and should only be done under medical supervision.