Calculate Your BMI, BMR, TDEE & Body Fat
Use our free online fitness calculators to find your Body Mass Index (BMI), Basal Metabolic Rate (BMR), Total Daily Energy Expenditure (TDEE), Body Fat Percentage, and Ideal Weight — powered by scientifically validated formulas.
What is BMI (Body Mass Index)?
BMI is a simple screening tool that measures body fat based on your height and weight. The formula is: BMI = weight (kg) ÷ height² (m²). A healthy BMI range is 18.5–24.9. BMI is used worldwide by doctors, nutritionists, and fitness professionals to assess whether a person is underweight, normal weight, overweight, or obese.
What is BMR (Basal Metabolic Rate)?
BMR represents the number of calories your body burns at rest — just to keep your heart beating, lungs breathing, and organs functioning. NutriBD uses the Mifflin-St Jeor equation, the gold standard recommended by the Academy of Nutrition and Dietetics: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161 (female) / + 5 (male).
What is TDEE (Total Daily Energy Expenditure)?
TDEE is the total number of calories you burn per day, including exercise and daily activity. It's calculated by multiplying your BMR by an activity factor. Knowing your TDEE helps you plan calorie intake for weight loss, maintenance, or muscle gain. Eat below TDEE to lose weight, at TDEE to maintain, or above TDEE to bulk.
How is Body Fat Percentage Calculated?
NutriBD uses the U.S. Navy Body Fat Formula, which estimates body fat percentage from neck, waist, and hip circumference measurements. This method is clinically validated and widely used by military and sports organizations. For men: measurements require neck and waist. For women: neck, waist, and hip measurements are needed..
