How to use the waist-to-hip ratio calculator
- Pick Male or Female, because the WHO cut-offs differ.
- Choose Inches or Centimeters. What you typed converts when you switch.
- Measure your waist halfway between your lowest rib and hip bone, after a normal breath out, tape level. Enter it as Waist.
- Measure the widest part of your buttocks and enter it as Hip.
How the ratio is calculated
Your ratio is waist divided by hip, so the unit cancels out: 32 in over 40 in equals 81.3 cm over 101.6 cm. It is rounded to two decimals, as the WHO reports it, before it is compared with the cut-off.
The WHO expert consultation on waist and hip measures (Annex A, Table A1) lists a ratio of 0.90 or higher for men and 0.85 or higher for women as substantially increased risk of metabolic complications. The same table lists a waist of over 94 cm (men) or 80 cm (women) as increased risk and over 102 cm or 88 cm as substantially increased. The report calls those waist figures an example from European data, not formal WHO recommendations.
The "waist that reaches the cut-off" box is the smallest waist, to the nearest tenth, whose rounded ratio hits the cut-off at your hip. The measuring steps above follow the WHO protocol in the same report.
Worked example
With the starting values (Female, waist 32 in, hip 40 in) the ratio is 32 ÷ 40 = 0.80, below the 0.85 cut-off for women. At a 40 in hip, 33.8 in is the smallest waist that shows 0.85. The waist alone is 32 × 2.54 = 81.3 cm, over the 80 cm line, so that box reads Increased risk even though the ratio is under its cut-off. The two measures can disagree.
Limits and edge cases
These cut-offs are for adults, not for children or pregnancy. Muscular hips lower the ratio without changing belly fat, and a bloated or sucked-in belly shifts the waist reading, so measure twice. It accepts a waist of 16 to 80 in (40 to 205 cm) and a hip of 20 to 80 in (50 to 205 cm), and flags ratios outside 0.5 to 1.5. WHR does not measure body fat directly: for that, try the body fat calculator or the BMI calculator, and for another heart marker the cholesterol ratio calculator.
Frequently asked questions
What is a good waist-to-hip ratio?
The WHO treats a ratio of 0.90 or higher in men and 0.85 or higher in women as substantially increased risk of metabolic complications. Below those numbers is the lower-risk side. A ratio is a screening signal, not a diagnosis.
How do I measure my waist and hips for WHR?
Stand upright and relaxed with a snug, level tape. Measure the waist halfway between your lowest rib and the top of your hip bone, after a normal breath out. Measure the hip around the widest part of your buttocks. Use the same units for both.
Is waist-to-hip ratio better than BMI?
Studies disagree. INTERHEART (27,000 people in 52 countries) found waist-to-hip ratio tracked heart attack risk far more strongly than BMI, but a 2011 analysis of 58 studies found that adding BMI, waist or WHR to standard risk factors such as blood pressure and cholesterol did not improve heart disease prediction. Treat WHR as one signal next to BMI.
Does my ethnicity change the cut-off?
It can. The WHO report found that Asian populations seem to reach increased risk at lower ratios, and gave 0.90 for men and 0.80 for women as example cut-offs. This calculator uses the general WHO values, so if you are of Asian descent, treat a ratio near the cut-off as a reason to ask your doctor.
Sources: WHO, Waist circumference and waist-hip ratio, 2011; Yusuf et al., Lancet 2005 (INTERHEART); Emerging Risk Factors Collaboration, Lancet 2011.