dragon roar stamina consumption

hello! i have a question regarding the dragon roar. does it consume a percentage of your max stamina or is it a fixed amount? all of my characters with dragon torso stone are at 40 end so i cant test this myself and i cant find a conclusive answer on the internet of all places.

Fixed amount. When I roar with my SL1 character it leaves me with zero stamina left, while roaring with my 40 end character leaves me with about half my bar.

thanks!