Compare a measurement with the distributions published in eleven studies, from Veale's systematic review (15,521 men) to single-country studies. The starting values are examples, replace them with your own.
State
Unit
Scale figure
Length
Along the top side, from the pubic bone (press the ruler against the bone) to the tip of the glans.
cm
Girth
With a tailor's tape around the shaft, at the base or mid-shaft, not under the glans.
cm
Categories
Category
Length
Girth
How many men
How to measure correctly
Length: correctRigid ruler on the top side, pressed in until it touches the pubic bone. Read at the tip of the glans.Length: common mistakeWithout pressing, the ruler starts at the skin and the reading comes out shorter. In 778 men the average difference between the two techniques was 1.8 cm (12.53 versus 14.34).GirthTailor's tape around the shaft, at mid-shaft or at the base: snug, without squeezing. Do not measure under the glans.
Measure in a room at a comfortable temperature: cold shortens flaccid measurements.
Stand up and hold the penis parallel to the floor.
For length, use a rigid ruler on the top side and press in to the pubic bone. Read at the tip of the glans, without counting any excess foreskin.
For the stretched measurement, while flaccid, gently pull the glans to full extension without pain.
For girth, use a flexible tape, or a strip of paper that you mark and then measure with the ruler.
Repeat two or three times at different moments and use the average.
Percentiles for the selected study
Measurement
5th
25th
50th (mean)
75th
95th
Men
Studies compared
Study
Erect length
Erect girth
Flaccid length
Flaccid girth
Stretched length
How to read the result
The percentile is the share of men with a smaller measurement than yours. At the 50th percentile, half of men measure less and half measure more.
The calculation uses a normal curve with the mean and standard deviation published by each study. It is the same method as Veale's nomograms.
The studies are not equivalent. Veale pools 20 studies with measurements taken by health professionals and is the most solid reference. Herbenick uses measurements taken by the participants themselves and has a much wider spread. Wessells, Schneider and Promodu have small samples.
Changing study can move the same value by many percentiles: it depends on population, age and measuring technique.
Ponchietti reports medians and a distribution that is not perfectly normal: there the percentile is an approximation.
The volume is a geometric estimate: it treats the penis as a cylinder with constant girth, so it tends to overestimate a little. The studies do not report volumes, so it has no percentile.
The categories are descriptive labels chosen for this tool, based on distance from the mean. They are not a medical classification.
Beyond the 2nd and 98th percentiles the estimate is indicative: real data are scarce at the extremes.
The figure is a diagram: it respects length and diameter (girth divided by pi), not the real shape.
This tool is informational and does not replace a medical assessment. If your measurement worries you, a urologist or andrologist can give a reliable opinion.