LayaqaWaist-to-height ratio: the simple number worth knowing
Divide your waist by your height. The result is a quick, useful check on the fat around your middle. Here's how to work it out and read it.
Body mass index (BMI) is the number most people know, but it only uses height and weight. It can't tell muscle from fat, and it says nothing about where you carry fat. That matters, because fat around your middle is more closely linked to health risks such as type 2 diabetes and heart disease than fat elsewhere.
Waist-to-height ratio is a simple way to check it.
How to work it out
Measure your waist and your height in the same unit, then divide one by the other:
Waist-to-height ratio = waist ÷ height
For example, a waist of 82 cm and a height of 175 cm give 82 ÷ 175 = 0.47.
Measure your waist halfway between the bottom of your lowest rib and the top of your hip bone, standing up, after breathing out normally. That's the method used in the guidance below. If you usually measure at your navel for your weekly check-ins, that's fine for tracking, but use the halfway point when you want to compare against these ranges.
How to read it
The UK's National Institute for Health and Care Excellence (NICE) recommends keeping your waist to less than half your height, and uses these ranges for adults:
| Ratio | What it suggests |
|---|---|
| 0.4 to 0.49 | Healthy central fat, no increased risk |
| 0.5 to 0.59 | Increased health risk |
| 0.6 or more | High health risk |
The same ranges apply to adults of any sex or ethnicity, which is part of the appeal: one rule of thumb, "keep your waist under half your height", works for almost everyone.
What it can and can't tell you
Waist-to-height ratio is a screening tool, not a diagnosis. It isn't meant for use during pregnancy, and children are assessed differently. A ratio in the higher ranges is a good reason to talk to a doctor, not a reason to panic.
It's most useful as a trend. Your height won't change, so your ratio moves only with your waist. Bring your waist down by a few centimetres and your ratio follows.
Check yours
The free body check on the Layaqa home page works out your waist-to-height ratio from your measurements, along with a body-fat estimate. If you track your waist in Layaqa every week, you'll see the trend without doing the maths yourself.
Layaqa is a measurement-tracking tool and doesn't provide medical advice. If you're worried about your health, speak to a healthcare professional.