What is BMI and how is it calculated?
BMI (Body Mass Index) is weight in kilograms divided by height in metres squared (kg/m²). It's a quick screening tool to indicate whether someone may be underweight, normal weight, overweight, or obese.
What are the BMI categories?
Under 18.5 is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, 30–34.9 is obese class I, 35–39.9 is obese class II, and 40+ is obese class III.
Can I use this calculator in feet, inches and pounds?
Yes — switch to Imperial mode and enter your height in feet and inches and weight in pounds. The calculator converts automatically.
Is BMI accurate for everyone?
BMI has limitations. It doesn't account for muscle mass, bone density, or fat distribution. Athletes may show as overweight despite being very healthy. Children and seniors also need different reference ranges.
What is a healthy weight for my height?
The calculator shows your personal healthy weight range (BMI 18.5–24.9) in both kg and lbs based on your height, making it easy to see your target range.