Penis Size

How can I tell if my baby’s penis is the normal size for his age?

Penis Size

Dr. Greene’s Answer:

In determining size, the “stretched penile length” is far more important than the “relaxed length.” To evaluate penis size, stretch the penis gently and measure from the bone at the base all the way to the tip. Be sure to depress the surrounding fat pad to get all the way to the base. Here are the normal values:

Average Stretched Penile Length 
(Adapted from Feldman KW, Smith DW. Journal of Pediatrics. 1975; 86:395):

Normal: Mean +/- 1 SD (inches)
Abnormal: Mean – 2.5 SD (inches)
0-5 months
1.5 +/- 0.3
6-12 months
1.7 +/- 0.3
1-2 years
1.9 +/- 0.3
2-3 years
2.0 +/- 0.4
3-4 years
2.2 +/- 0.4
4-5 years
2.2 +/- 0.4
5-8 years
2.4 +/- 0.4
8-11 years
2.5 +/- 0.4
5.2 +/- 0.6


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Dr. Alan Greene

Dr. Greene is the founder of (cited by the AMA as “the pioneer physician Web site”), a practicing pediatrician, father of four, & author of Raising Baby Green & Feeding Baby Green. He appears frequently in the media including such venues as the The New York Times, the TODAY Show, Good Morning America, & the Dr. Oz Show.

  1. KLEE

    My son just turned 2 years old and his penis is 3 CM is this normal? When he was born a urologist questioned if he had micropenis the endocrinologist didn’t say, just that he was smaller than average.

  2. maulik

    my son is 5 year old ,his penis size is 20 cm, pls suggest it is normal or not


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