24.2
Normal weight
Under 18.5NormalOver 25Obese 30+
BMI is a quick screening measure, not a diagnosis. It doesn’t distinguish muscle from fat and isn’t validated for children, athletes or during pregnancy. For medical advice, speak with a qualified health professional.
BMI calculator (Body Mass Index)
Body Mass Index estimates whether your weight is in a healthy range for your height. Enter your details in metric or imperial units to get your BMI, the World Health Organization category, and the weight range that would put you in the healthy band for your height.
WHO categories
- Under 18.5 — underweight
- 18.5 – 24.9 — healthy weight
- 25 – 29.9 — overweight
- 30 and above — obese
Frequently asked questions
How is BMI calculated?
BMI = weight (kg) ÷ height (m)². This tool does the maths for you in either metric or imperial units.
What is a healthy BMI?
The World Health Organization considers 18.5 to 24.9 a healthy weight. Below 18.5 is underweight, 25–29.9 is overweight and 30+ is obese.
Is BMI accurate for everyone?
No. BMI is a population screening tool. It can misclassify very muscular people, and it is not intended for children, pregnant women or the very elderly. Treat it as a starting point, not a diagnosis.