A worked example: 190cm height, 16cm wrist
Running the calculator's formula on a height of 190cm and a wrist circumference of 16cm divides 190 by 16 to get a ratio of 11.88, rounded to two decimal places. Since 11.88 is above the calculator's 10.4 cutoff, the result is "Ectomorph" — the calculator's label for a narrower wrist relative to height.
The formula: dividing height by wrist circumference
The calculator computes a single ratio — height in centimeters divided by wrist circumference in centimeters — and sorts that ratio into one of three bands: above 10.4 is "Ectomorph," 9.6 up to and including 10.4 is "Mesomorph," and below 9.6 is "Endomorph." A height of 165cm with a 17cm wrist gives a ratio of 9.71, which falls inside the 9.6-10.4 Mesomorph band.
Another worked example: 160cm height, 19cm wrist
Running the same formula on a height of 160cm and a wrist circumference of 19cm gives a ratio of 8.42 — below the 9.6 cutoff — so the calculator returns "Endomorph." Compared to the 190cm/16cm example above, a shorter height paired with a proportionally thicker wrist pushes the ratio well down into the Endomorph band rather than up into Ectomorph.
Why this is a rough estimate, not a diagnosis
The calculator's own documentation describes this as a simplified heuristic — the same numeric bands popularly used on wrist-based frame-size charts — rather than a clinical somatotype assessment. A true somatotype classification (the Heath-Carter method) requires multiple skinfold and bone-width measurements, so a single height-to-wrist ratio should be treated as a quick, rough starting point rather than a precise result.