How bmi & calorie target calculator works
This tool computes your Body Mass Index (BMI) and your daily calorie target in one step. Enter your height and weight (metric in cm/kg or imperial in feet, inches and pounds), your sex, age, activity level and goal. BMI is calculated as weight in kilograms divided by height in metres squared (kg/m^2) and sorted into the standard Underweight, Normal weight, Overweight and Obese categories.
Your daily calorie target uses the Mifflin-St Jeor resting metabolic rate (BMR) formula, which estimates the energy your body burns at rest: for men BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5, and for women BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161. This BMR is multiplied by an activity factor (1.2 for sedentary up to 1.9 for very active) to get your Total Daily Energy Expenditure (TDEE) - the calories you need to maintain your current weight.
Your goal then shifts the target: lose weight applies a 500 kcal/day deficit (about 1 lb/week), gain weight applies a 500 kcal/day surplus, and maintain keeps your TDEE as-is. The tool also shows the healthy weight range for your height (BMI 18.5-24.9). Everything runs in your browser with no data sent anywhere. These estimates are for healthy adults and are not medical advice - athletes, pregnant or breastfeeding people, and anyone with a medical condition should consult a professional.