I would expect a gallon and a half, but get more, especially for a first build. On my first build I lost a lot of epoxy due to errors, sometimes they "went off" in hot temperatures, and sometimes I did just silly things, like spilling is all over while concentrating on the wet out. A big oval on the floor has a permanent plastic oval where I tripped over a fresh 6 ounce batch. Maybe I was more clumsy than average, but these things happen.