Accurate, standardized measurements are necessary for comparing results to clinical data or selecting sexual health products like condoms. Determining both length and girth requires precise methods to ensure reliable outcomes. This guide provides the medically accepted instructions for self-measurement. Obtaining these standardized numbers is straightforward when the proper tools and techniques are applied consistently.
Essential Tools and Preparation
Accurate measurement requires specific tools depending on the dimension recorded. For length, use a rigid ruler or non-flexible tape to ensure a straight-line reading. Girth, which is a circumference, requires a flexible, non-stretchable cloth measuring tape, like one used for tailoring. If flexible tape is unavailable, non-elastic string can be wrapped around the shaft and then measured against a rigid ruler.
The fully erect state is the standard used in most clinical studies. Penile size can fluctuate based on temperature and levels of arousal. Measuring in a warm, comfortable environment minimizes natural retraction and allows for the most consistent comparison with established medical averages.
Accurate Measurement of Length
The gold standard for determining length is the “bone-pressed” measurement, also known as Bone-Pressed Erect Length (BPEL), which provides the true anatomical length. Place the rigid ruler on the dorsal side of the penis, which is the side facing the ceiling. The end of the ruler must be pressed firmly into the pubic bone, pushing past any pubic hair or fat pad until the bone is felt. This technique eliminates length concealed by the suprapubic fat pad, especially in individuals with higher body mass.
The measurement is taken from this firmly pressed point to the tip of the glans. If the penis has a natural curve, use a flexible tape measure to follow the contour for the most accurate reading. Medical professionals rely on the bone-pressed length because non-bone-pressed measurements vary significantly and are less useful for clinical comparison against established population norms.
Accurate Measurement of Girth
Girth refers to the circumference of the shaft and is measured at the thickest point, typically along the mid-shaft or near the base. Using the flexible, non-stretchable measuring tape, gently wrap it around the shaft one time. The tape should be snug against the skin but not so tight that it compresses the tissue or causes indentation.
The number where the end of the tape overlaps indicates the circumference. If string was used, mark the overlap point, straighten the string, and measure that length with a ruler. Taking multiple readings along the thickest region and averaging the results can improve reliability. This circumference measurement is frequently used for selecting the appropriate condom size.
Contextualizing Your Results
The measurements obtained are best understood when compared to data compiled from large, professional studies rather than anecdotal self-reports. A systematic review involving over 15,000 men found the average erect length to be approximately 5.17 inches and the average erect girth to be about 4.59 inches, based on measurements taken by health professionals. These figures represent the 50th percentile, meaning half of the population falls above and half falls below these values.
If measurements fall significantly outside the standard range, particularly the lower end, discuss them with a healthcare provider. An adult penis measuring less than 3.67 inches when gently stretched is medically termed a micropenis. Concerns about severe curvature, which may suggest conditions like Peyronie’s disease, or any significant pain should also prompt a medical consultation.