I have a very big upward curve and cannot measure with a ruler. I measure with a tailor tape and push it BP like a ruler and make the tape follow the path of the curve. For example, if I measure with a ruler, my BP is 6.29” If I measure with the tape it is 7.086” so there IS a difference.
I think that what it is truly important is that you stay consistent with your method of measure so in the future if I measure and see a 7.5 BP with the tape then I would know for a fact that I have grown regardless of the method that I use to measure.
On a side note, if I am 100% hard, it is IMPOSSIBLE to straight out my penis, the only way to do it would have to be breaking the thing lol.
Finally, I love my upward curve, it stimulates the g-spot so well and almost all the girls have told me that they never felt this “itchy pleasurable feeling that makes me want to pee” thing in their lives ;) .