Free BMI Calculator
The BMI Calculator computes Body Mass Index from your height and weight, with support for metric and imperial units, and shows your category on the standard scale.
How to use the BMI Calculator
- 1 Choose metric or imperial units.
- 2 Enter your height and weight.
- 3 Read your BMI together with the category band it falls into.
- 4 Check the healthy weight range shown for your height, which is more actionable than the single number.
How to Use
Choose metric or imperial, enter your height and weight, and your BMI and category appear instantly. BMI is a general screening measure, not a medical diagnosis.
- Metric and imperial units
- Category (underweight / normal / overweight / obese)
- Visual scale indicator
Frequently asked questions
Is BMI a good measure of health?
It is a useful population-level screen, not a personal diagnosis. BMI cannot distinguish muscle from fat, so athletes often read as overweight, and it says nothing about where fat is stored — which matters more for metabolic risk than the total.
What are the BMI categories?
Under 18.5 is underweight, 18.5 to 24.9 is healthy, 25 to 29.9 is overweight and 30 or above is obese. These thresholds are defined for adults; children and teenagers are assessed on age-specific percentile charts instead.
Should BMI be adjusted for different ethnicities?
Several health bodies think so. The WHO recognises that some populations develop type 2 diabetes and cardiovascular disease at lower BMI values, and suggests a lower overweight threshold of 23 for people of South Asian descent.
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