Ask Kayla Quinn

Measure from the side of the penis. Make sure you are as hard/erect as you can possibly be. Now, hold your cock below the head and place a ruler next to it with your other hand. You should feel the ruler gently pressing against your pubic bone. Measure from here. Do not cheat by using a measuring tape and starting underneath everything near your asshole! If anything, claim it is a little smaller than it is, rather than bigger. That is one lie no man can live down getting caught telling! Being proven wrong when you claimed it is smaller than it is would be MUCH better! If you are wanting to measure how fat it is, that is the girth of your soldier, break out the measuring tape. Fully erect again, hold your fuck stick out, parallel to the ground. Wrap the tape around your penis, but do not pull the tape too tight! There you go! Now you know how big your package is!

This is the standardized method that researchers use to measure the "average penis size" (which is 6" - 6.5" long and measures 5" - 5.5" in girth, according to recent studies).