Enter your weight and height to find your Body Mass Index (BMI) — and see whether it falls in the underweight, healthy, overweight or obese range, plus the healthy weight range for your height.
How to use this BMI calculator
- Choose Metric (kg, cm) or Imperial (lbs, ft/in).
- Enter your weight and height, then press Calculate My BMI.
- You will see your BMI, your category, and the healthy weight range for your height. Nothing you type is sent anywhere; the calculation happens on your own phone or computer.
BMI is a general guide, not a medical diagnosis. Muscle, age, pregnancy and some health conditions can affect what a healthy BMI means for you — talk to a doctor for personal advice.
Frequently asked questions
What is a good BMI?
For most adults, a BMI from 18.5 to 24.9 is classed as healthy. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese.
How is BMI calculated?
BMI is your weight in kilograms divided by your height in metres squared. In imperial units it is 703 times your weight in pounds divided by your height in inches squared.
Is BMI accurate for everyone?
Not always. Very muscular people can show a high BMI without extra body fat, and older adults or pregnant women need different guidance. Use BMI as a starting point, not the full picture.
Is my weight stored or shared?
No. This tool works completely inside your browser. Your numbers are never uploaded, saved or shared.
Free BMI Calculator — fast, private, no sign-up.