BMI Calculator for a Quick Health Check
Enter your height and weight to calculate your Body Mass Index, understand your BMI category, and view a healthy weight range for your height.
Enter your details
Use the unit system that feels most familiar.
Your result will appear here
Complete the form and select “Calculate My BMI” to see your score, category, healthy weight range, and guidance.
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Understanding your BMI
What BMI measures
BMI compares your weight with your height. It is commonly used as a general screening measure rather than a complete health diagnosis.
Standard adult ranges
Below 18.5 is underweight, 18.5–24.9 is generally considered healthy, 25–29.9 is overweight, and 30 or above falls within obesity ranges.
Use it in context
Muscle mass, body composition, pregnancy, age, ethnicity, and medical conditions can affect how BMI should be interpreted.
Frequently asked questions
What is a healthy BMI?
For most adults, a BMI from 18.5 to 24.9 is generally described as the healthy or normal-weight range. Individual circumstances may require a more personalised interpretation.
Does age change the BMI formula?
The basic BMI formula does not change with age. However, children and teenagers are usually assessed with age- and sex-specific BMI percentiles rather than adult fixed categories.
Can muscular people have a high BMI?
Yes. BMI does not distinguish between muscle and body fat, so highly muscular people may receive a higher BMI even when their body-fat level is not high.
Is my information stored?
No. This calculator performs the calculation in your browser and does not need to save the age, height, or weight you enter.