How to use the waist-to-height ratio calculator
- Choose inches or centimeters.
- Measure your waist around the body at the level of the navel, after breathing out normally, and enter it.
- Enter your height in the same unit.
- Read the ratio, your waist as a percent of height and how your waist compares with half your height.
Formula
Waist-to-height ratio = waist / height
Percent of height = ratio x 100
Half of your height = height / 2
Both measurements use the same unit, so the ratio itself has no unit. It is the same whether you measure in inches or centimeters, apart from rounding.
A 34 inch waist and a 68 inch height
The ratio is 34 / 68 = 0.50, which is 50.0% of height. Half of 68 inches is 34 inches, so the waist matches half of the height exactly.
In metric, an 86 cm waist and a 170 cm height give 86 / 170 = 0.506, which rounds to 0.51. A 40 inch waist with a 70 inch height gives 0.57, and the waist is 5 inches more than half of the height.
How to measure
Stand straight with relaxed shoulders. Wrap a flexible tape around your middle at the level of your navel, snug against the skin but not squeezing, and read it after a normal breath out. Measure height without shoes against a wall. Measure at about the same time of day each time, because a meal or a long day can change a waist reading by a little.
What the number is and is not
A waist-to-height ratio is a simple way to relate your waist to your height. People of different heights can compare their waist on the same scale this way. The page shows how your waist compares with half your height because that comparison is widely discussed, but it does not tell you whether a result is healthy, and it gives no categories or targets.
One measurement says little about health on its own, and the ratio does not account for age, muscle, body shape or medical history. Talk with a doctor or another health professional about what your measurements mean for you. To record measurements over time use the Body Measurement Tracker Printable, and for other general measures see the BMI Calculator and the Body Fat Calculator.
Assumptions and limits
- The waist and height are measured in the same unit by the same method.
- The accepted ranges are 10 to 150 inches for the waist and 30 to 100 inches for height, or the same in centimeters.
- The page reports a number and a comparison only. It does not label results.
- Nothing is uploaded. Calculations run in your browser, and the result is general information, not medical advice.
Frequently asked questions
Does it matter if I use inches or centimeters?
No, as long as both measurements use the same unit. The ratio is the same either way. The page also shows your measurements in both units.
Is this a diagnosis?
No. It is a ratio of two measurements and nothing more. A health professional can tell you what your measurements mean for you, taking your age, history and other factors into account.
Where exactly should I measure my waist?
Many guides suggest the level of the navel. Others use the narrowest point of the trunk or a point midway between the ribs and the hip bone. Pick one method and use it every time so your numbers can be compared.
Why does the page compare my waist with half my height?
It is a simple reference point that is often discussed. The comparison shows by how much your waist is over or under that line. It is not a target or a limit.