Waist-to-height ratio calculator
Your waist-to-height ratio is a quick check on fat stored around the middle. NHS guidance is to keep your waist below half your height. Enter your measurements to see your ratio and category.
How it works
The ratio is your waist measurement divided by your height, in the same unit. Because both are lengths, the units cancel, so a waist of 85 cm and a height of 175 cm gives the same answer as the equivalent figures in inches. NHS guidance sets the healthy line at 0.5: your waist should be less than half your height. The tool sorts the result into four bands. Under 0.4 is below the usual range, 0.4 to 0.49 is healthy, 0.5 to 0.59 shows increased fat around the middle, and 0.6 or more is high.
Waist-to-height ratio adds something BMI misses. BMI can flag a muscular person as overweight and can miss fat stored deep around the organs, which is the fat most linked to heart disease and type 2 diabetes. Measuring the waist targets that directly, which is why the ratio is used alongside BMI rather than instead of it.
Worked example
Take a waist of 85 cm and a height of 175 cm. Dividing 85 by 175 gives 0.49, which lands in the 0.4 to 0.49 band. To reach the 0.5 healthy line at this height, the waist would need to be about 88 cm, so this example is 3 cm over the target. Trimming the waistline by that much would move the ratio back under 0.5.
Common questions
What is a healthy waist-to-height ratio?
Under 0.5 is the healthy target used in NHS guidance, so your waist should measure less than half your 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 your ribs and the top of your hips, roughly level with your 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 carries more health risk. Many clinicians now 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 lets you switch between centimetres and inches.
What if my ratio is high?
A higher ratio is linked to a greater chance of type 2 diabetes, high blood pressure and heart disease. Small, steady changes to diet and activity that trim the waistline lower the risk. Speak to your GP if you are concerned.