Waist To Hip Ratio Calculator
Waist-to-hip ratio divides one circumference by another and returns a single unit-free number. The arithmetic takes seconds; the judgement lies in measuring at the right landmarks and in reading the result as a screening signal rather than a diagnosis.
Waist-to-hip ratio
0.8
- Waist converted to inches
- 31.4961
- Hip converted to inches
- 39.3701
- Waist that would reach the 0.90 male threshold
- 90
Values update as you type. This calculator covers the single scenario its formula assumes — see Common Mistakes for what it leaves out.
The formula this calculator uses
WHR = waist / hip
- waist
- Waist circumference, at the midpoint between the lowest rib and the hip bone
- hip
- Hip circumference, at the widest point of the buttocks
- WHR
- Waist divided by hip; dimensionless, so it carries no unit
- 0.90 / 0.85
- WHO substantially increased risk thresholds for men and for women
How to check the result by hand
- 1
Measure the waist at the right landmark
Find the midpoint between the lowest rib and the top of the hip bone, usually just above the navel. Keep the tape horizontal and snug without compressing the skin, and read at the end of a normal exhale. Measuring at the navel instead can add several centimetres, which is enough to shift the ratio across a threshold.
- 2
Measure the hip at its widest point
Wrap the tape around the fullest part of the buttocks, checking that it stays level all the way round. In the worked example this is 100 cm, and a slip of a few centimetres here changes the denominator directly. Use the same tape and the same posture as for the waist.
- 3
Use one unit for both circumferences
Centimetres or inches, but not a mixture. If the waist is in centimetres and the hip in inches, convert first: 80 cm is 31.496062992125985 in and 100 cm is 39.37007874015748 in. Because the ratio cancels the unit, the choice does not change the answer, only the risk of an arithmetic slip.
- 4
Divide the waist by the hip
80 / 100 = 0.8. Carry the division at full precision and round only at the end. The result is dimensionless, so it is written without a unit, and it can be compared directly with the WHO thresholds of 0.90 for men and 0.85 for women.
- 5
Compare against the thresholds and your own trend
Place the number against 0.90 and 0.85, then against your previous readings. A single value of 0.8 is below both cut-offs, while 0.9 sits exactly on the male line. Treat the comparison as a screening signal, and look at the direction of travel over several measurements rather than one reading in isolation.
For worked examples, common mistakes and the limits of this formula, read the full How To Calculate Waist To Hip Ratio page.