What is the proper way of measuring your penis length?

[Vagination]

There are so many factors that change the result.

If I measure from the side, I have a longer length. I've also read that you're supposed to push to the pubic bone to eliminate the fat factor. Well, doing that adds a lot of length for me. My penis is also a little curved so am I allowed to use a tape measure to take into account curvature?

Measuring length is so much more complicated than girth.