Waist-to-height ratio calculator
Waist-to-height ratio compares waist measurement against height to check for fat stored around the middle, following NHS guidance that keeping the waist below half of height is the healthy target. This calculator divides the entered waist by height and sorts the result into one of four bands, and the figure is general information, not a diagnosis.
How is waist-to-height ratio calculated?
The ratio is the waist measurement divided by height, using the same unit for both.
Because both figures are lengths, the units cancel, so a waist of 85 cm and a height of 175 cm gives the same ratio as the equivalent measurements in inches.
NHS guidance sets the healthy line at 0.5, meaning the waist should measure less than half of height.
The tool sorts the result into one of four bands, shown below.
| Ratio | Band |
|---|---|
| Under 0.4 | Below the usual range |
| 0.4 to 0.49 | Healthy |
| 0.5 to 0.59 | Increased fat around the middle |
| 0.6 or more | High |
Waist-to-height ratio adds something BMI misses.
BMI can flag a muscular person as overweight and does not show where fat sits.
Measuring the waist targets fat stored around the organs directly, and the NHS links that fat to a greater risk of heart disease and type 2 diabetes, which is why the ratio is often read alongside BMI rather than instead of it.
What would the ratio be for an example waist and height?
Take a waist of 85 cm and a height of 175 cm.
Dividing 85 by 175 gives 0.49, which falls in the 0.4 to 0.49 band.
Reaching the NHS 0.5 healthy line at this height would need a waist of about 88 cm, so this example sits 3 cm from that line.
This is general information rather than medical advice, and a doctor should be consulted about any health concern.
Common questions
How is waist-to-height ratio calculated?
The ratio is waist measurement divided by height, using the same unit for both measurements, so centimetres and inches give the same result. NHS guidance sets the healthy target below 0.5, meaning the waist should measure less than half of height. The tool then sorts the ratio into four bands, from below the usual range up to high. This is general information and does not amount to a diagnosis.
What would the ratio be for an example waist and height?
Take a waist of 85 cm and a height of 175 cm. Dividing 85 by 175 gives a ratio of 0.49, which falls in the 0.4 to 0.49 band under NHS guidance. Reaching the 0.5 healthy line at that height would need a waist of about 88 cm. This example is general information only and is not a diagnosis.
What is a healthy waist-to-height ratio?
Under 0.5 is the healthy target used in NHS guidance, so a waist should measure less than half of height. Between 0.5 and 0.59 points to more fat around the middle than is ideal, and 0.6 or more counts as high.
How do I measure my waist correctly?
Find the point halfway between the bottom of the ribs and the top of the hips, roughly level with the navel. Breathe out naturally, do not pull the tape tight, and take the reading against bare skin for accuracy.
Is waist-to-height ratio better than BMI?
They measure different things. BMI uses weight and height but ignores where fat sits, while waist-to-height picks up fat stored around the organs, which the NHS links to greater health risk. Many clinicians look at both together.
Does the ratio work in inches or centimetres?
Either, as long as both measurements use the same unit. The ratio is waist divided by height, so the units cancel out. This tool allows switching between centimetres and inches.
What if my ratio is high?
A higher ratio is linked by the NHS to a greater chance of type 2 diabetes, high blood pressure and heart disease. This calculator gives general information only and does not recommend any change to diet or activity. A GP can advise on personal circumstances and any health concern.
Sources & Rate Verification
Rates verified against official statutory guidance on 6 September 2026.