Well.....11, since we will include the champ of each division. Going off of UFC's rankings, not anybody elses. Used Wiki for heights with occasional backup verification from Sherdog. I am sick as fuck right now and super bored, so here we go for some useless ass info!

Average height:

HW: 6.23 ft (Champ is 5'11, the tallest is Volkov at 6'7, the shortest is Hunt at 5'10) Average reach is 78.13

LHW: 6.16 ft (Champ is 5'11, the tallest is Gus at 6'5, the shortest is Ilir at 5'10) Average reach is 76.95

MW: 6.08 ft (Champ is 6', the tallest is Stylebender at 6'4, the shortest is Kelvin at 5'9) Average reach is 75.13

WW: 5.94 ft (Champ is 5'9, the tallest is Magny at 6'3, the shortest is RDA at 5'8). Average reach is 74

LW: 5.78 ft (Champ is 5'10, the tallest is Vick at 6'3, the shortest is a 4 way tie at 5'9 for Lee, Porier, Alvarez, McGregor, the tallest is Vick at 6'3) Average reach is 72.9

FW: 5.64 ft (Champ is 5'11, the tallest is a tie with Holloway the champ and Moicano at 5'11, the shortest is Edgar at 5'6) Average reach is 69.72

BW: 5.46 ft (Champ is 5'6.5, the tallest is Cruz at 5'8, the shortest are a tie with Dodson and Lineker at 5'3) Average reach is 64.13

FLY: 5.40 ft (Champ is 5'3, the tallest is Moreno at 5'7, the shortest is the champ at 5'3) Average reach is 66.18