BMI Calculator
Body Mass Index for adults
Body Mass Index (BMI) is a widely used screening measure that estimates whether your weight is appropriate for your height. It is not a diagnostic tool and does not directly measure body fat, but it gives a quick, standardized reference point used by health organizations worldwide.
How BMI is calculated
BMI is calculated by dividing your weight in kilograms by the square of your height in meters: BMI = weight (kg) / height (m)².
Example calculation
A person weighing 70 kg who is 1.75 m tall has a BMI of 70 / (1.75 × 1.75) = 22.9, which falls within the normal weight range defined by the World Health Organization.
BMI categories (WHO)
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obesity |
FAQ
Is BMI accurate for everyone?
BMI does not distinguish between muscle and fat, so it can overestimate body fat in muscular individuals and underestimate it in older adults with reduced muscle mass.
What is considered a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered within a healthy range, though individual health also depends on factors such as waist circumference and muscle mass.
Does BMI apply to children?
No. Children and teenagers require age- and sex-specific growth charts rather than the adult BMI scale.