Waist-to-hip ratio calculator

What is a waist-to-hip ratio calculator?

A waist-to-hip ratio (WHR) calculator divides your waist circumference by your hip circumference to produce a single, unitless number that describes how your body stores fat. A higher ratio means relatively more weight is carried around the abdomen, while a lower ratio means more is carried around the hips.

The World Health Organization (WHO) uses waist-to-hip ratio as a simple indicator of health risk linked to central (abdominal) fat. Because the thresholds differ between women and men, the calculator asks for your sex and then reports both the ratio and the matching low, moderate, or high risk band.

How does the calculator work?

You provide two circumferences, measured with a soft tape measure:

• Waist circumference — around the narrowest part of the torso, usually just above the navel.
• Hip circumference — around the widest part of the hips and buttocks.

Both measurements must be in the same unit. Since the ratio divides one length by another, the units cancel out and the result is the same whether you measure in centimeters or inches. The calculator then compares the ratio against the WHO thresholds for your selected sex and assigns a risk band.

Formula

The waist-to-hip ratio is simply:

$\text{WHR} = \frac{\text{Waist}}{\text{Hips}}$

The WHO risk bands are:

• Female: WHR $\le 0.80$ low risk; $0.81$ to $0.85$ moderate risk; $> 0.85$ high risk.
• Male: WHR $\le 0.95$ low risk; $0.96$ to $1.0$ moderate risk; $> 1.0$ high risk.

Examples

1. Female — waist 70 cm, hips 95 cm:

   • WHR = $\frac{70}{95} \approx 0.7368$
   • Below the female low-risk threshold of 0.80, so the band is low risk.

2. Male — waist 95 cm, hips 100 cm:

   • WHR = $\frac{95}{100} = 0.95$
   • Exactly at the male low-risk threshold of 0.95, so the band is low risk.

3. Female — waist 90 cm, hips 95 cm:

   • WHR = $\frac{90}{95} \approx 0.9474$
   • Above the female high-risk threshold of 0.85, so the band is high risk.

Practical notes

• Measure on bare skin or over thin clothing, keep the tape level and snug but not compressing, and exhale normally before reading.
• WHR captures fat distribution rather than total body fat, so it complements weight-based metrics rather than replacing them.
• For a fuller picture of body composition and health, pair WHR with the waist-to-height ratio and BMI.
• The bands are general guidance, not a diagnosis. Discuss any concerns about abdominal fat and cardiovascular risk with a healthcare professional.

FAQs

Which measurements do I need?

You need two circumferences, the waist and the hips, both taken in the same unit.

Does the unit matter?

No. The ratio divides waist by hips, so the units cancel and you get the same value in centimeters or inches as long as both use the same unit.

Why does the calculator ask for my sex?

Men and women tend to store fat differently, so the WHO uses different risk thresholds for each. Selecting your sex ensures the ratio is compared against the correct band.

How is WHR different from BMI?

BMI uses height and weight to estimate whether your overall weight is in a healthy range, while WHR describes where fat is stored. Two people with the same BMI can have very different waist-to-hip ratios.