Objective To systematically review and create nomograms of flaccid and erect penile size measurements. Methods Study key eligibility criteria: measurement of penis size by a health professional using a standard procedure; a minimum of 50 participants per sample. Exclusion criteria: samples with a congenital or acquired penile abnormality, previous surgery, complaint of small penis size or erectile dysfunction. Synthesis methods: calculation of a weighted mean and pooled standard deviation ( sd) and simulation of 20 000 observations from the normal distribution to generate nomograms of penis size. Results Nomograms for flaccid pendulous [ n = 10 704, mean ( sd) 9.16 (1.57) cm] and stretched length [ n = 14 160, mean ( sd) 13.24 (1.89) cm], erect length [ n = 692, mean ( sd) 13.12 (1.66) cm], flaccid circumference [ n = 9407, mean ( sd) 9.31 (0.90) cm], and erect circumference [ n = 381, mean ( sd) 11.66 (1.10) cm] were constructed. Consistent and strongest significant correlation was between flaccid stretched or erect length and height, which ranged from r = 0.2 to 0.6. Limitations: relatively few erect measurements were conducted in a clinical setting and the greatest variability between studies was seen with flaccid stretched length. Conclusions Penis size nomograms may be useful in clinical and therapeutic settings to counsel men and for academic research. [ABSTRACT FROM AUTHOR]