Health calculator
Waist-to-Hip Ratio Calculator
Calculate waist-to-hip ratio from waist and hip measurements, then compare the result with broad risk-context reference points and related body-composition tools.
On this page
Calculate a unitless waist-to-hip ratio
Divide waist circumference by hip circumference to compare the two measurements. Enter both in centimetres: the form and supporting measurement tiles use cm, while the ratio itself has no unit.
Formula and reference points
Waist-to-hip ratio = waist in cm ÷ hip in cm. The displayed ratio is rounded to two decimal places. The category uses the unrounded ratio and compares it with 0.90 for the male reference or 0.85 for the female reference. A result equal to or greater than the selected point enters the tool's above-reference category.
Take and enter the measurements
- Use a flexible tape and a consistent measurement protocol, keeping the tape level without compressing the skin. The WHO report linked below explains the measurement landmarks.
- Enter waist and hip circumferences in cm. Convert inches to cm before using these fields.
- Select the reference sex used by the comparison, then choose whether the measurements were taken today or estimated.
- Calculate and read the ratio, reference point and original measurements together. The measurement-note selector records context; it does not change the ratio.
Worked waist-to-hip examples
Below the selected reference
A waist of 78 cm and hips of 100 cm give 78 ÷ 100 = 0.78. With the female reference selected, the comparison point is 0.85 and this result is below it.
Exactly at a reference point
A 90 cm waist and 100 cm hips give 0.90. With the male reference selected, the result meets the 0.90 point, so the tool places it in the at-or-above category. Rounding can make two nearby ratios look alike: classification still uses the original division.
Record both measurements when tracking
Changes in waist and hips can offset each other. Keep the two centimetre measurements, date and measurement method alongside the ratio instead of tracking the ratio alone.
Measurement mistakes to avoid
- Entering inches into fields labelled cm.
- Changing the tape position, clothing or tape tension between checks.
- Reading a two-decimal display as a precise boundary between healthy and unhealthy.
- Treating the selected reference sex or a measurement note as an adjustment for age, ethnicity, pregnancy or an individual medical history.
What the reference comparison can tell you
The WHO expert consultation on waist circumference and waist–hip ratio reviews the use of these measurements in screening. Its Annex A summarises the commonly used 0.90 male and 0.85 female points. Measurement protocol, age, sex and ethnicity affect interpretation; a single cut-off does not describe every adult equally.
This calculator performs the division and a broad adult reference comparison. It does not measure body fat, diagnose disease or assess children, pregnancy or postpartum changes. A result below the reference is not a guarantee of health. Discuss concerning changes or clinical risk with an appropriate health professional.
Waist-to-Hip Ratio Calculator FAQs
Must I enter centimetres?
Yes. This interface labels the inputs and measurement tiles in cm. Convert an inch measurement to centimetres first. The final waist-to-hip ratio is unitless.
Why does a ratio of 0.85 meet the female reference?
The calculator uses an at-or-above comparison: an unrounded ratio of at least 0.85 meets the female reference, while at least 0.90 meets the male reference.
Does selecting Estimated measurement change the result?
No. That option is shown as a note beside the result; only waist and hip measurements determine the ratio. The reference sex changes the comparison point.
Does a lower ratio rule out a health problem?
No. Waist-to-hip ratio supplies one screening measure and cannot replace symptoms, medical history or a clinical assessment.
Keep the ratio and measurements together
Use centimetres throughout this tool, calculate waist ÷ hips and check the selected reference. For repeat measurements, keep the tape method consistent and record both circumferences as well as the unitless ratio.