Hi VampireBat. First of all, what is most important is that you find a consistent way to measure for you. That way you can track your own gains confidently. For me, what seems most reliable is to simply subtract my average fat pad measurement (0.5”) from my BPEL measurement to get my NBPEL (Currently 6.56-0.5=6.06”). I don’t think it’s really the best way to do it, but my weight and fitness are pretty consistent, even as I’ve aged it seems. For other guys, this would be a bad idea, because their weight fluctuates, which greatly impacts fat pad. I may continue to “dick around” with this over the coming months/years though, and find another way to measure NBPEL. There’s just too much variability with that measurement for me, so I don’t emphasize it much.
I do agree with qweqweqad1 that the best way to measure BPEL is with a vertical ruler! I think it’s the only reliable option.