How is BMI calculated?

BMI is calculated by dividing weight in kilograms by height in meters squared (kg/m²). In imperial units: 703 × weight (lb) ÷ height (in)².

What is a healthy BMI?

For adults, a BMI between 18.5 and 24.9 is generally considered within the normal range, though individual context matters.

Is BMI accurate for everyone?

BMI is a screening tool and does not directly measure body fat. It may be less informative for athletes, older adults, and some populations.

Health tools

BMI Calculator

Estimate body mass index from height and weight to understand general weight categories.

Height (cm)

Weight (kg)

Results update automatically. Formula: weight (kg) ÷ height (m)², or 703 × weight (lb) ÷ height (in)².

Enter valid height and weight to see your BMI, category, and healthy weight range.

How BMI is calculated

Body Mass Index (BMI) is weight in kilograms divided by height in meters squared (kg/m²). Imperial: 703 × weight (lb) ÷ height (in)².

• Underweight: BMI below 18.5
• Normal: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obese: BMI 30 and above

What's next?

Want a personalized daily calorie estimate based on your stats?

Try the Calorie / TDEE Calculator

These calculators are for educational purposes only and are not a substitute for professional medical advice, diagnosis, or treatment. Read our medical disclaimer.

Frequently asked questions

How is BMI calculated?: BMI is calculated by dividing weight in kilograms by height in meters squared (kg/m²). In imperial units: 703 × weight (lb) ÷ height (in)².
What is a healthy BMI?: For adults, a BMI between 18.5 and 24.9 is generally considered within the normal range, though individual context matters.
Is BMI accurate for everyone?: BMI is a screening tool and does not directly measure body fat. It may be less informative for athletes, older adults, and some populations.