Originally Posted by thecrow19
My girl keeps saying I have a “big” penis. I just laugh at her when she says it and get awkward. I know I’m not “big” but the thing is I believe her that she THINKS my dick is big. My girth is above average at 5.80”+(over 2” in diameter) but I only have a 6.35” in length. Would a girthier penis also be classified as a “big” penis. I always just view a big penis as 7”+ in length. To me big is related to length.
Her perception of you being big has to do with volume. The volume of a penis is affected much more by girth than length. This is because the contribution of girth to volume is squared while the contribution of length is not. If you really want to see this, the formula for the volume of a penis (approximating it by a cylinder) is V = L*G^2 / (4*pi) where L is the length and G is the girth. This is approximately equal to V = L*G^2 / 12.56.
Your perception of size has to do with length. This is an illusion, however. Our eyes don’t detect true girth changes. They only detect width changes. Your width, w, is given by w = G / pi or about w = G / 3.14. As you can see, a small girth change will not contribute very much to width because it is spread out (i.e. divided by pi).
Here is an example:
For you, L = 6.35” and G = 5.8”. This gives V = 17 cubic inches. If we perturb your length by 0.25 inches to L = 6.6”, V = 17.68 cubic inches. On the other hand, if we keep your length the same and add 0.25 inches to your girth, we get V = 18.5 cubic inches when G = 6.05”. The length change leads to a 3.9% increase in volume, while the girth change leads to an 8.8% increase in volume. This is why a woman will feel girth changes much more than length changes.
Your current width is 1.85 inches. Adding 0.25” to your girth gives you a new width of 1.93”. That difference isn’t easily perceptible to the unaided human eye. Thus, a woman will feel the difference in girth but you won’t see it.