Body metrics

BMI and Waist-to-Height Ratio Calculator

View two common screening measures together without treating either as a diagnosis.

Use the toolFree · No account required

Enter your measurements

Waist circumference is optional; add it to see both measures together.

The calculation runs on your device; your health inputs are not sent or stored.

Your result

Enter valid adult measurements and calculate.

BMI does not distinguish muscle mass. Waist-to-height ratio is also a screening indicator, not a diagnosis. Do not use during pregnancy or under age 18.

Put your measurements in context

Review the explanation and limitations below before drawing conclusions from the numbers.

Find a fitness trainer

Quick guide

Read both measures in context

BMI is a broad screening measure made from height and weight. Waist-to-height ratio compares waist circumference with height and gives a practical central-adiposity screen. They do not answer the same question.

How to use it

  1. 1Enter height and weight in consistent units.
  2. 2Measure your waist at the same point without holding your breath.
  3. 3Do not use either result as a diagnosis or target on its own.

How should you read it?

BMI may sit in a reference range while waist-to-height is higher. That is not a contradiction; the measures describe different things.

Keep the limits in view

BMI cannot distinguish muscle from fat. Waist-to-height is a practical screen and the 0.5 threshold is not a diagnosis.

What this tool cannot do

BMI does not distinguish muscle from fat. Waist-to-height ratio is a general screening indicator, not a diagnosis.

NICE measurement guidance

Sources last checked: September 2026