Knowing that he is 181cm (5'11") I did some proportional math.
I found two photos, in which he appears to be fully soft, he measured about 16cm(6.25"). When hanging heavy, he is about 26cm (10.2"). In the photos were he is just starting to lift he is about 30cm (11.8"). But when he is fully erect he curves back and looses some length, along the topside, and is then "only" 28cm (11"), but along the underside, from where the ball sack meets the shaft, he measures a huge 34cm (13").
Soft he has a diameter of 4.8cm (1.9") and when hard it is 6cm (2.4"); times pi that would be 18.8cm (7.4") around.