BMI Calculator
Calculate your Body Mass Index and find your healthy weight range
What is BMI?
Body Mass Index (BMI) is a numerical value calculated from your height and weight. It provides a quick snapshot of whether your weight falls within a healthy range for your height. While BMI is not a direct measure of body fat, it is a widely used screening tool that correlates with more precise measures of body composition.
BMI is calculated by dividing your weight in kilograms by the square of your height in metres. A BMI between 18.5 and 24.9 is considered normal weight for most adults. Below 18.5 indicates underweight, 25 to 29.9 is overweight, and 30 or above falls into the obese category.
BMI Categories
Underweight (below 18.5) may indicate malnutrition, an eating disorder, or other health conditions. Normal weight (18.5 to 24.9) is associated with the lowest risk of weight-related health conditions. Overweight (25 to 29.9) carries increased risk of cardiovascular disease, type 2 diabetes, and joint problems. Obese (30 and above) significantly raises the risk of serious health conditions.
Limitations of BMI
BMI does not distinguish between muscle and fat. A heavily muscled athlete may have a high BMI while carrying very little body fat. Conversely, an older individual with low muscle mass may show a normal BMI while carrying excess fat. For a more complete picture of your body composition use BMI alongside our Body Fat Calculator and Ideal Weight Calculator.
BMI Calculator — Frequently Asked Questions
What is a healthy BMI?
A healthy BMI for adults is between 18.5 and 24.9. A BMI below 18.5 is considered underweight, 25–29.9 is overweight, and 30 or above falls into the obese category according to WHO classifications.
How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by the square of your height in metres. In imperial units, divide weight in pounds by height in inches squared, then multiply by 703.
Is BMI accurate for athletes?
BMI is not accurate for athletes or heavily muscled individuals because it does not distinguish between muscle and fat. Use BMI alongside our Body Fat Calculator for a more complete picture of your body composition.
Does BMI differ for men and women?
The standard BMI formula and healthy ranges are the same for adult men and women. However, women naturally carry more body fat at the same BMI than men, which is why BMI is best used alongside body fat percentage.