Global Data Explained

Veale D, et al. Am I normal? A systematic review and construction of nomograms for flaccid and erect penis length and circumference in up to 15 521 men. BJU Int. 2015;115(6):978–986.

This systematic review pooled data from up to 15,521 men across multiple clinical studies. Crucially, measurements were taken by health professionals using a standardized, bone-pressed protocol, not self-reported. That combination of scale and rigor is why the resulting nomograms remain the reference for global averages: an erect mean of 13.12 cm length (SD 1.66) and 11.66 cm girth (SD 1.10).

The per-country averages behind the world map and the country selector are compiled from public aggregators (e.g. WorldData.info), which themselves blend whatever studies and surveys exist per country. That provenance has real limits:

• Mixed measurement methods: some sources are clinically measured, many are self-reported, and self-reporting reliably skews upward.
• Small or absent samples: for many countries the underlying data is a handful of observations, or an estimate inferred from neighbors.
• Publication and selection bias: studies that exist are not a random sample of a country's population.

The result: country figures are indicative estimates. They are not peer-reviewed per country, and no confidence intervals survive the compilation process.

The compilations publish means only, no spread. To draw a distribution for a country, this app assumes the global erect SDs: 1.66 cm for length and 1.10 cm for girth. That is a reasonable first approximation, but it means every country curve has the same shape; only its center moves.

Where a country-specific SD ever becomes available, the dataset supports it directly and it is used instead. Flaccid comparisons never use country data at all, because no compiled flaccid dataset exists, so flaccid mode always uses the global baseline.

Treat a country baseline as a rough orientation, not a verdict. A percentile against a country average inherits every uncertainty above: the shifted center plus an assumed spread. For anything resembling a clinically meaningful comparison, use the global Veale baseline, and for actual health questions, a clinician, not a dashboard.