Average Penis Length: Erect, Stretched & Flaccid
In the 2015 systematic review by Veale and colleagues, mean erect length was 13.12 cm (5.16 inches), based on 692 measurements. The same review reported mean stretched length of 13.24 cm (5.21 inches) from 14,160 measurements and mean flaccid length of 9.16 cm (3.61 inches) from 10,704 measurements. Methods differ between studies, so compare like with like.
How doctors measure erect length
Medical researchers use the "bone-pressed erect length" (BPEL) method. The ruler is placed along the top of the erect shaft and pressed firmly past the fat pad until it reaches the pelvic bone. Measuring without pressing the bone can under-read actual length by up to 1.5 inches in men with higher body fat.
What is considered a normal length?
The study provides a reference mean, not a clinical threshold for normality. A measurement alone cannot predict sexual function or fertility.
Flaccid length vs erect length
Resting flaccid length varies greatly depending on temperature, stress levels, and hydration. A man whose soft penis is 2.5 inches can easily achieve an erect length of 5.5 inches, because flaccid size does not predict erect expansion.
My Size Report provides a private, calculator-led way to understand measurements against published research. Results are informational and should not be treated as medical advice.