Waist to Height Ratio Calculator for Women | Female Atlas

How does the waist to height ratio calculator work? You enter your waist and your height in the same units, inches or centimeters, and it divides the first by the second. The units cancel out, so the result is the same whichever you choose. It is one sum, and it says nothing about your strength, your fitness or how you feel.

Where does the half-your-height rule come from? From that same pooled analysis, which also found the ratio outperformed waist circumference alone as a screen for diabetes, hypertension and cardiovascular disease. In the UK, the NHS gives the same advice in plain words: keep your waist to less than half your height.

Does waist size matter on its own? It can add a second view, though the ratio is the stronger screen. For adult women, the US National Heart, Lung, and Blood Institute links a waist of more than 35 in with higher health risk; in centimeters, the unit used in the UK, researchers draw the same line at 88 cm (Ford, Maynard and Li, JAMA, 2014).

Is it suitable for girls and teens? This calculator is built for adults. The studies behind the rule pooled adults, and the 35 in line is an adult women's figure, so a result for a girl or teen who is still growing isn't one to read into. If you have a question about growth, her doctor (GP in the UK) is a good place to start.

What does a higher result mean? First, that you are in plenty of company: in the same JAMA survey data, 64.7% of US women aged 20 and over had a waist over 88 cm in 2011 to 2012. A waist at or above half your height is a screen, not a diagnosis, and it's worth treating it as the start of a conversation, not a verdict on your health.

Common questions

How often should I check my waist to height ratio?

There is no need to check often. We suggest every few months at home is plenty. If measuring starts to feel like a worry and not a help, it's fine to stop and bring it up at a routine visit instead.

Does my life stage change how the calculator works?

The sum is the same at every adult stage, including the reproductive years outside pregnancy. If you are in the years leading up to your final period, perimenopause weight gain covers how bodies change then; menopause weight gain is for the time around the final period itself, and postmenopause weight gain is for the years after.

Who should skip this calculator?

The NHS suggests not using its waist to height tool if you are pregnant, have an eating disorder or a growth disorder, or are an adult with a BMI over 35. If one of those applies to you, it's worth asking a doctor (GP in the UK) about a check that fits better.

What if my waist is half my height or more?

One reading doesn't decide anything. It's worth seeing a doctor (GP in the UK) if your waist stays at or above half your height when you measure again a few months later, or if it has been a while since your blood pressure and blood sugar were checked, since those are among the things the ratio was studied as a screen for. One test that may come up is A1C (called HbA1c in the UK); on the CDC's A1C levels chart, a normal result is below 5.7%.

Next steps

A good place to start is measuring your waist and height and entering them above. From there, our tools section has more calculators to explore, and the HbA1c page explains the blood sugar test in plain words if you would like to read up before an appointment. Your stage, body and history are your own, so this is not one size fits all, and you decide what fits you.

Waist to height ratio calculator: is your waist under half your height?