Your Body Mass Index is
What is BMI and how is it calculated?
Body Mass Index (BMI) is a quick screening number that compares your weight to your height. It’s worked out as your weight in kilograms divided by your height in metres squared (the calculator handles pounds and feet/inches for you). A BMI under 18.5 is considered underweight, 18.5–24.9 is a healthy range, 25–29.9 is overweight, and 30 or more is in the obese range.
BMI is a rough screening tool, not a diagnosis. It doesn’t tell muscle from fat, so athletes and very muscular people can read “high” while being healthy, and it isn’t validated for children or pregnancy. Use it as a starting point and talk to a doctor about what’s right for you.
Frequently Asked Questions
What is a healthy BMI?
For most adults a BMI between 18.5 and 24.9 is considered a healthy range. Below that is underweight; 25–29.9 is overweight; 30 and above is in the obese range.
Is BMI accurate for everyone?
No. Because it only uses height and weight, it can’t distinguish muscle from fat. Athletes may score high despite low body fat, and it isn’t designed for children, pregnant people, or the very elderly.
What should I do if my BMI is outside the healthy range?
Treat it as a prompt, not a verdict. Waist measurement, body-fat percentage and how you feel matter too. A doctor or dietitian can give guidance tailored to you.
How is BMI calculated from pounds and inches?
Multiply your weight in pounds by 703, then divide by your height in inches squared. This calculator does that automatically when you choose US units.