You started the tape at 1.5 and it runs to 8, so that would put your dick at 6.5 inches. Seriously, what is the point in cheating. The tape should start at 0". By the way the correct way of measuring is standing up, sitting down is also considered cheating. You are nowhere near 8 inches dude. You are about 6.25 inch.
Listen your dick is above average and sorry to nitpick, I am just tired of seeing every man online cheating about his penis size when it comes to a measurement. Just be honest for once and accept what you have. Nice 6.25 inch cock.