First of all, what guy doesn't own a ruler or tape measure? I'd be willing to bet that EVERY may in America has several.
More importantly, there is no method (other than surgery) of increasing the size of someone's penis. And the surgery usually just removes fat or other tissue from the base of the pelvis, allowing more of the penis to be exposed there (for better insertion into someone). No pills or magic elixirs, exercises, or anything else is going to increase the length of your penis. You might get some temporary stretching or swelling (e.g., from a [words=https://officialhydromaxpump.com/?uid=6&oid=2&affid=98]penis pump[/words]), but that's all.