If you are taking about a cubic yard, it is 40.5 80lb bags. A bag of 80lb concrete is roughly 2/3 cubic ft.

A cubic yard is 3 ft x 3 ft x 3 ft = 27 cubic ft.

27 cubic ft / .6666 cubic ft = ~80.5

A cubic yard is 3 ft x 3 ft x 3 ft = 27 cubic ft.

27 cubic ft / .6666 cubic ft = ~80.5