Free BMI Calculator — Body Mass Index Calculator Online

Enter your details

Unit

Weight (kg) Height (m)

How to use the BMI calculator

Select metric (kg and metres) or imperial (pounds and feet/inches).
Enter your weight and height in the chosen units.
Click Calculate BMI. Your BMI and category (Underweight / Normal / Overweight / Obese) will be shown.

Why use a BMI calculator?

BMI is a simple indicator of weight relative to height. It’s useful for general health awareness. It does not replace medical advice — body composition and health vary. This tool computes BMI only; we don’t store your data.

Frequently asked questions

How is BMI calculated?

BMI = weight (kg) / height (m)². We also accept imperial units (lbs and feet/inches) and convert internally.

What do BMI ranges mean?

Under 18.5: underweight; 18.5–24.9: normal; 25–29.9: overweight; 30+: obese. These are general guidelines, not a substitute for medical advice.

Is my data stored?

No. Your height and weight are only used to compute BMI and are not saved.

Free BMI Calculator — Body Mass Index Online