First you measure on top from the pubic bone out.

Forearm size is generally under 10 inches from elbow to wrist.
John Holmes for example was stated as being up to 14 inches, in reality 9-3/4 inches according to a member of the LA Hung Jury who worked with John who reported this to author Gary Griffin who wrote extensively about enlargement in the late 1990′s.

The other way is to put one hand palm down on the shaft against the pubic bone and the other hand palm down on the shaft, so all the knuckles line up – you can’t exaggerate bone. Hands are usually about three to three and a half inches outside knuckle to outside knuckle. If you can see the head out from both hands you are about seven to eight inches.

A 10 inch penis is rare. One in every 100,000 people.

Every inch is an angry inch.

cheers