How is the waist-to-height ratio calculated?

WHtR = waist circumference ÷ height, with both measured in the same unit, so the result is a unitless number. The well-known rule is to keep your waist below half your height (WHtR under 0.5).

What is a healthy waist-to-height ratio?

Common adult bands are: under 0.40 take care (possibly underweight), 0.40 to 0.49 healthy, 0.50 to 0.59 increased risk, and 0.60 and over high risk. The single boundary most people remember is 0.5 — your waist should be under half your height.

Is WHtR more accurate than BMI?

WHtR captures central (abdominal) fat that BMI can miss, and many researchers find it a useful complementary screen. It is still a screening tool, not a diagnosis. Use it alongside BMI and professional advice rather than instead of them.

Does the unit (cm or inches) change my result?

No. Because you divide waist by height in the same unit, the units cancel and the ratio is identical whether you measure in centimetres or inches. Just keep both measurements in the same unit.

Where exactly should I measure my waist?

Measure at the midpoint between your lowest rib and the top of your hip bone (the iliac crest), breathing out normally. Keep the tape level and snug without compressing the skin for a repeatable reading.

Is WHtR valid for children or during pregnancy?

No. The 0.5 boundary and the adult risk bands are not validated for children or during pregnancy, where body proportions differ. Use a tool designed for those groups and consult a clinician.

Does my measurement leave my device?

No. Your waist and height are used only inside your browser to compute the ratio. Nothing is stored, logged or transmitted.

Waist-to-Height Ratio Calculator

Waist-to-height ratio calculator

The waist-to-height ratio (WHtR) is one of the simplest central-fat health screens available. It compares your waist circumference to your height to estimate how much fat you carry around the abdomen — a stronger predictor of metabolic risk than overall weight alone. The rule of thumb is memorable: keep your waist to less than half your height. It works for adults of any build and is often used alongside BMI.

How it works

The tool divides your waist by your height, both entered in the same unit:

WHtR = waist ÷ height

Because both measurements share a unit, it cancels out and the result is a plain unitless number — identical in centimetres or inches. Your ratio is then matched to a risk band, and the tool also shows your healthy waist ceiling, which is simply half your height (converted to centimetres for reference).

WHtR	Band
Below 0.40	Take care (possibly underweight)
0.40 – 0.49	Healthy
0.50 – 0.59	Increased risk
0.60 and over	High risk

Example

Suppose your waist is 80 cm and your height is 175 cm. Then WHtR = 80 ÷ 175 = 0.457, which falls in the healthy band. Your healthy waist ceiling is half of 175 cm = 87.5 cm, so you have about 7.5 cm of headroom before crossing the 0.5 boundary.

WHtR is a screening guide, not a diagnosis, and is not validated for children or during pregnancy. All maths runs locally in your browser — nothing is uploaded.