BMI Calculator

What this tool does

Calculates body mass index from weight and height and shows which category the figure falls into under the common classification.

When to use it

• Wanting a quick indicator of your weight relative to your height.
• Filling in a health form that asks for it.
• Tracking how the figure changes over time.

How to use it

1. 1Enter your weight and height in the units shown.
2. 2Run the calculation.
3. 3Read the index value and its category.

A practical example

Limitations

• This tool is for general information only and is not a substitute for advice from a doctor or dietitian.
• The index does not distinguish muscle from fat: a muscular athlete can land in the "overweight" band in excellent health, and someone with little muscle can sit in the normal band with a high body-fat percentage.
• The classification comes from studies of particular populations and may not apply equally across all ethnicities and builds.
• It is not suitable for children, adolescents or pregnant people, who have different growth charts.

Privacy and processing

All calculations happen on your device and your health data is never sent to a server.

Technical notes

• The index is weight in kilograms divided by height in metres squared — the standard agreed formula.