Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Calculate your waist-to-height ratio -- a simple health-risk screening alternative to BMI.
0.49
Waist-to-height ratio (WHtR) is a widely cited, simple alternative to BMI for health screening -- the commonly published guidance is straightforward: keep your waist circumference under half your height.
Enter your waist circumference and height (same units). Your ratio and whether it's in the healthy range appear instantly.
WHtR = Waist Circumference / Height
Commonly cited healthy threshold: WHtR < 0.5.
WHtR is sometimes cited as tracking cardiovascular/metabolic risk at least as well as BMI, while being simpler to calculate and interpret across different body types and ages. Pair it with the Waist-to-Hip Ratio Calculator for a fuller picture.
Take someone who is 70 inches tall with a 34 inch waist. The ratio is 34 divided by 70, about 0.486, which is below the 0.5 threshold, so the tool reports it as within the healthy range. If the waist grows to 36 inches at the same height, the ratio becomes about 0.514 and crosses the line. In this example, 35 inches is exactly half of 70, so that waist would sit right on the boundary. The tool treats only values strictly below 0.5 as healthy, so a ratio of exactly 0.50 is not flagged as in range.
34 / 70 = 0.486 (under 0.5). 36 / 70 = 0.514 (over 0.5).
Because the guidance is simply "waist under half of height," you can work backward. Multiply your height by 0.5 to get the largest waist that stays under the threshold. Someone 66 inches tall would want a waist under 33 inches, and someone 180 cm tall would want under 90 cm. This makes the tool handy for setting a tangible goal, such as trimming a couple of centimeters over a few months, and then confirming progress with a fresh measurement.
The ratio does not distinguish muscle from fat and cannot see visceral fat directly. It is a quick screen, not a diagnosis, and this page is educational rather than medical advice. If your ratio is above 0.5, or you have concerns about heart health, blood sugar, or blood pressure, discuss your measurements with a doctor rather than relying on a single number.
It's a simple, widely publicized rule of thumb correlating with lower cardiometabolic risk across a range of heights and ages, easier to remember than an absolute waist measurement.
Some research suggests WHtR tracks health risk comparably to or better than BMI since it directly reflects central/abdominal fat, but no single ratio is a complete health assessment on its own.
The 0.5 guidance is generally cited for adults; consult pediatric-specific guidance for children.
No. The tool marks the healthy range only when the ratio is below 0.5, so 0.50 or higher is outside it.
Multiply your height by 0.5. For example, at 68 inches the target waist is under 34 inches; at 170 cm it is under 85 cm.
No. It uses only waist and height, so it applies the same single threshold to every input. Other factors are outside what it evaluates.
Possibly. The ratio reflects waist size only, so a thick, muscular midsection can raise the ratio without the same meaning as abdominal fat. Use it alongside other measures.
Reference: Centers for Disease Control and Prevention