Waist-to-Height Ratio Calculator
One tape measure, one rule of thumb: keep your waist to less than half your height. It takes ten seconds, it costs nothing, and unlike BMI it doesn’t punish you for carrying muscle.
Your ratio
Use the same unit for both. Measure your waist just above your hipbones, after breathing out.
Waist-to-height ratio
0.54
half your height is 33.5 in — the number to keep your waist under
Band
Increased central adiposity
at or above 0.5 — the point NICE suggests keeping below
Why this one is useful if you lift. NICE states these classifications can be used for adults of both sexes and all ethnicities with a BMI under 35 — explicitly including adults with high muscle mass. That’s the gap BMI leaves: muscle inflates BMI, but it doesn’t inflate your waist.
A rough guide for planning, not medical advice or a diagnosis — NICE itself notes the ratio should be interpreted with caution because it isn’t a direct measure of central adiposity. Tape measurement also carries real error, so measure the same way each time and watch the trend rather than one reading. Anything about what this means for you belongs with your healthcare provider.
Why this beats BMI if you’re training
BMI has a well-known blind spot: it can’t tell muscle from fat, so building muscle pushes your BMI up exactly as fat would. Waist-to-height doesn’t have that problem, and NICE says so explicitly — its bands can be used for adults of both sexes and all ethnicities with a BMI under 35, including adults with high muscle mass.
It’s also more responsive to the change you actually want. As you lose fat on a GLP-1 while holding onto muscle, your waist shrinks and your ratio falls — even in the weeks the scale sits still. That makes it a better weekly companion than a weigh-in.
Two honest caveats. NICE notes the ratio should be interpreted with caution because it isn’t a direct measure of central adiposity. And tape measurement carries real error between people and between attempts — so measure the same way every time and read the trend, as the measurement guide explains.
A shrinking waist tells you the fat is going. It can’t tell you the muscle is staying — that takes training you actually do. Mira builds short, form-scored strength sessions around your week, so both halves of the picture move the way you want.
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