Well i have my own technic for measuring my "status" ...what i do is, i have measured the distance from my thumb to my index finger when in a stretched hand position and that gave me an easy 8" ( 20cm ) so i usually do a flaccid stretch and put my thumb at the pubic bone and see where the tip goes, usually it surpasses the index finger by a 1/2 inch so that gages my bpfsl quick and no need for a ruler...result? 8.5 bpfsl and that keeps me happy cause i started with a bpfsl of 7" 3 months ago ehehehe