BMI Calculator Enter your weight and height to calculate Body Mass Index (BMI) and get a category. Weight (kg) Tip: Use kilograms (kg). Decimals allowed. Height (cm) Tip: Use centimeters (cm). Decimals allowed. Calculate BMI Reset Copy Result Result: Enter values to calculate. BMI categories Underweight: < 18.5 Normal weight: 18.5 – 24.9 Overweight: 25.0 – 29.9 Obese: ≥ 30.0 BMI is a screening tool and does not diagnose body fatness or health.