I have not ordered it yet. I'm looking at 3 yards (a little over 2 1/5 meters). I think it's only going to take 1 1/2 to 2 yards to make the actual costume, with the stretchy material in between the neoprene. I don't know for sure yet, but that's my best guess. The other 1/12 is for screw ups or another costume should the first one work well.
I actually found that pattern at a sewing class I took last week, and I bought it as I knew it was one of the few people had utilized for this costume. I haven't bought from Jabbadashery yet, but I've got the black matte lycra already. Hopefully, I can buy the neoprene in two weeks.
Depends on what size you are (look at the top for xs, s, m, l, xl). Then follow down. Depends on the fabric width as to how much you need to buy (if I remember correct it was closer to 45"). The first number is imperial - yards I think. The second number in brackets is in meters.