Fewer girth figures

Girth data are scarcer because fewer studies measured it, fewer still measured it erect, and older studies often did not record where on the shaft. In Veale et al. (2015), BJU International, erect circumference rests on 381 men, against 14,160 for stretched length. None of this means girth matters less.

Not every study measured it

Length is the measurement almost every study includes, because it is the figure most consistently requested and the easiest to standardise on a rigid ruler. Circumference requires a second instrument and a second protocol, and a meaningful number of the studies later pooled into the literature simply did not collect it, which shrinks the girth sample before anything else happens.

Fewer still measured it erect

Among the studies that did record girth, fewer took an erect reading than a flaccid one. Flaccid measurement is faster to obtain in a clinical setting, and some protocols stopped there for girth even when they went on to record length in more than one state. That leaves the erect girth figure - the one most people actually want to compare against - resting on a smaller sub-sample than either the flaccid girth figure or any of the length figures. Single cohorts can outnumber the pooled erect figure: Habous et al. (2015), Journal of Sexual Medicine, measured erect girth in 778 men at one group of Saudi clinics, reporting a mean of 11.50 cm (SD 1.74).

The site was not always recorded

Girth varies along the shaft, and the convention is to measure at the midpoint - a rule the correct method covers in full. Not every study uses the midpoint either - Habous et al. (2018) took girth "at the base of the penis" - and not every older study specified where on the shaft its reading was taken, and a girth figure without its site attached is harder to pool cleanly with figures that do specify it, because base, midshaft and glans readings are not the same measurement.

What this means for reading a girth figure

A thinner pool means a wider margin of uncertainty around the reported girth means than around the length means, on top of whatever spread exists in the population itself - the actual figures and what that spread implies are covered separately. It is not a reason to distrust the girth data outright, only a reason to hold the girth mean slightly less tightly than the length mean, since fewer men and less consistent protocol went into producing it.

None of this scarcity has anything to do with a photograph-based judgement of size or shape, which Rate Cock and services like it are built around answering instead, from a different kind of input entirely. An image model faces its own, unrelated limit here - it cannot read a circumference off a picture regardless of how much clinical data exists to compare it against. A scored photo on Penis Rater or a verdict from a human judge are both answering a different question than "how many centimetres," and neither is affected by how thin the girth literature happens to be.