Waist-to-Height Ratio Calculator

Work out your waist-to-height ratio from a waist and height measurement, see which health category it falls into, and check the simple rule of keeping your waist under half your height.

Load a body example or enter your own measurements
Units
Sex (refinement note only)
Your waist-to-height ratio
0.00
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Waist divided by height, both in the same unit.
Where your ratio sits
Horizontal band scale showing the waist-to-height ratio category 0.50 - half your height 0.30 0.40 0.60 0.70 Take care Healthy Increased High risk 0.45

The marker shows your ratio on a scale from 0.30 to 0.70. The dashed line is the 0.50 boundary: the simple public rule is to keep your waist below half your height.

Category reference (adults)
RatioCategoryWhat it means

These boundaries apply to all adults regardless of sex. Waist-to-height ratio is also used for children, but interpretation differs there; this tool is built for adults.

The simple rule: keep your waist under half your height.

Half of your height is 89 cm. Your waist is 80 cm, which is below that line - on track.

For beginners: how to read this
One ratio, no scales neededWaist-to-height ratio compares one measurement to another, so a tape measure is all you need - no weighing and no body-fat device.
Aim for the healthy bandA ratio between 0.40 and 0.49 is the healthy zone. Crossing 0.50 means central fat is building up and risk starts to rise.
Measure the waist correctlyFind the point midway between your lowest rib and the top of your hip bone. Breathe out gently, keep the tape snug and level, and do not pull it tight.
It is a screen, not a verdictThe ratio flags central body fat at a glance. It does not measure fitness, muscle or overall health on its own - use it alongside other checks.
This is a general screening estimate based on the Ashwell waist-to-height boundaries, not a medical diagnosis. It does not account for pregnancy, athletic build, individual health conditions or body composition. Speak to a qualified healthcare professional about your personal health and before making changes.

To get a result, load a body example or enter your own measurements: waist and height. Use the unit toggle to switch between centimetres and inches, and keep both measurements in the same unit. The headline figure is your waist-to-height ratio together with its health category.

How the ratio is calculated

Waist-to-height ratio, often shortened to WHtR, is one measurement divided by another: ratio equals waist divided by height. Because both values use the same unit, the result is a plain number with no unit attached. A ratio of 0.50, for example, means your waist is exactly half your height.

What the categories mean

The calculator places your ratio into the four Ashwell categories, which apply to all adults regardless of sex:

  • Below 0.40 – take care: under the healthy zone and may indicate being underweight.
  • 0.40 to 0.49 – healthy: central body fat is in a healthy range.
  • 0.50 to 0.59 – increased risk: central fat is raised and linked to higher risk of heart and metabolic problems.
  • 0.60 and above – high risk: central fat is high and the risk to long-term health is considerable.

The simple rule: waist under half your height

The easiest takeaway is the 0.50 boundary: keep your waist measurement below half your height. The calculator shows your half-height figure and tells you directly whether your waist sits below, on, or above that line. The colour band scale marks where your exact ratio falls and how close it is to the next category.

How to measure your waist correctly

Measurement accuracy matters more than the formula. Find the point midway between the bottom of your lowest rib and the top of your hip bone, usually around the level of the navel. Breathe out gently, keep the tape snug but not tight, and make sure it is level all the way around. Measure your standing height without shoes. Sex is offered only as a small refinement note – the category boundaries themselves do not change between men and women.

What is not included

This is a screening estimate, not a medical assessment. It does not account for pregnancy, a very muscular build, individual health conditions, age-related changes or detailed body composition. Waist-to-height ratio is also used for children, but the interpretation differs and this tool is built for adults. For anything concerning your personal health, speak to a qualified healthcare professional.