Measure in the right place
Use a flexible tape midway between the lowest rib and top of the hip. Keep it horizontal, snug but not tight, and take the reading after a natural breath out.
Central adiposity screening
Waist-to-Height Ratio Calculator
Divide your waist measurement by your height and see whether your waist is below half your height. Use centimetres or feet and inches.
Waist and height
Calculate your ratio
Adult screening tool · Best used alongside BMI
Private by design. Your waist, height and result stay in this browser.
Your measurements
Measure accurately
1
Find the bottom of your ribs and top of your hips. Measure midway between them, just above the belly button, after breathing out naturally.
Your result
Waist-to-height ratio
Healthy central adiposity
Your waist is below half your height and falls within the standard healthy central adiposity range.
0.46
Half your height
87.5 cm
Waist compared with half-height
7.5 cm below
Calculation
80 ÷ 175
This is a screening measure, not a diagnosis. NICE recommends waist-to-height ratio alongside BMI for adults whose BMI is below 35. It should not replace professional assessment.
A useful second measurement
Why waist-to-height ratio adds context to BMI
BMI estimates general weight status. Waist-to-height ratio focuses on central adiposity—the fat carried around the abdomen—and uses one memorable boundary: waist below half of height.
Use it alongside BMI
The ratio can reveal central adiposity that BMI alone may miss and can be useful for adults with high muscle mass. It is complementary, not a replacement for a full assessment.
One standard boundary
NICE applies the same classifications to adults of both sexes and all ethnicities. Health risks still depend on medical history, blood pressure, blood tests and other factors.
Adult ratio categories
How to interpret waist divided by height
The ratio has no unit. Centimetres and inches produce the same answer when both measurements use the same system.
When not to rely on this result
- During pregnancy or when a condition changes waist shape or height.
- If an eating disorder has been diagnosed or may be present.
- As a substitute for age-appropriate child growth assessment.
- As the main risk measure when an adult BMI is 35 or higher.
| Classification | Ratio |
|---|---|
| Below classified range | Below 0.4 |
| Healthy central adiposity | 0.4 to <0.5 |
| Increased central adiposity | 0.5 to <0.6 |
| High central adiposity | 0.6 or above |
Below 0.4? NICE does not assign this range a lower-risk classification. Recheck the measurement and seek professional advice if it is unexpected or concerning.
Guidance references: NICE waist-to-height recommendations and NHS waist-to-height guidance.
Waist-to-height questions
Waist-to-Height Ratio Calculator FAQ
How do I calculate my waist-to-height ratio?
Measure your waist and height in the same units, then divide waist circumference by height. A waist of 80 cm and height of 175 cm gives 80 ÷ 175 = 0.46.
What is a healthy waist-to-height ratio?
NICE classifies 0.4 to 0.49 as healthy central adiposity, 0.5 to 0.59 as increased central adiposity, and 0.6 or above as high central adiposity. The memorable general message is to keep your waist below half your height.
How should I measure my waist?
Find the bottom of your ribs and the top of your hips. Place the tape midway between them, usually just above the belly button. Keep the tape level and snug without compressing the skin, breathe out naturally, then read the measurement.
Is waist-to-height ratio better than BMI?
They answer different questions. BMI compares total weight with height, while waist-to-height ratio estimates central adiposity. NICE recommends using waist-to-height ratio alongside BMI in adults with a BMI below 35.
Do the thresholds differ for men, women or ethnic backgrounds?
NICE uses the same waist-to-height classifications for adults of both sexes and all ethnicities. Individual health still depends on many factors, so the ratio is a screening measure rather than a diagnosis.
Can I use this calculator if my BMI is 35 or higher?
Waist-to-height ratio adds less predictive information when adult BMI is 35 or higher, so NHS and NICE guidance does not recommend relying on it in that situation. Ask a healthcare professional for an appropriate assessment.
Who should not use the standard interpretation?
Do not rely on the standard adult interpretation during pregnancy, with an eating disorder, or with a growth disorder or another condition affecting height. Children and teenagers should use age-appropriate guidance with a parent, carer or healthcare professional.
Can I calculate the ratio with inches?
Yes. The ratio has no unit, so centimetres or inches produce the same result as long as waist and height use the same unit. The US mode accepts waist in inches and height in feet and inches.
Does Bobek store my measurements?
No. Your waist, height and result remain in your browser and are not sent to or stored by Bobek.