BMI Calculator
Calculate your Body Mass Index in seconds. Enter your height and weight in metric or imperial — works for anyone, anywhere in the world.
<18.5 Normal
18.5–24.9 Overweight
25–29.9 Obese
≥30
| Category | BMI Range | Your Weight At This Height |
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Frequently Asked Questions
What Is BMI?
Body Mass Index, commonly known as BMI, is a numerical value calculated from a person’s height and weight. It provides a simple, widely used screening tool to categorize weight status and identify potential health risks associated with being underweight, at a healthy weight, overweight, or obese. Healthcare providers around the world use BMI as a quick initial assessment — not as a diagnostic tool, but as a useful starting point for health conversations.
The BMI formula is the same worldwide: weight in kilograms divided by height in meters squared. Our calculator accepts both metric inputs using kilograms and centimeters, and imperial inputs using pounds, feet, and inches. It converts automatically and displays your BMI alongside the standard World Health Organization classification ranges.
It is important to understand that BMI has limitations. It does not directly measure body fat percentage and does not account for differences in muscle mass, bone density, age, sex, or ethnicity. Athletes with high muscle mass may have a high BMI without excess body fat, while older adults may have a healthy BMI with significant body fat. Always discuss your results with a healthcare professional for personalised guidance.
Frequently Asked Questions
What is a healthy BMI range? According to the World Health Organization, a BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is classified as obese. These ranges apply to adults aged 18 and over.
Is BMI accurate for everyone? BMI is a population-level screening tool and has limitations at the individual level. It tends to overestimate body fat in muscular people and underestimate it in older adults who have lost muscle mass. It does not distinguish between fat and muscle.
Does BMI differ between men and women? The BMI calculation and classification ranges are the same for both men and women. However, women naturally carry more body fat than men at the same BMI, and some health organizations recommend slightly different interpretations by sex for clinical purposes.
What BMI is considered obese? A BMI of 30 or higher is classified as obese by the WHO. Obesity is further divided into Class I from 30 to 34.9, Class II from 35 to 39.9, and Class III at 40 and above, sometimes referred to as severe obesity.