How many gallons would hold in a cylindrical tank 4 feet diameter and 4 feet tall?

1 cubic foot = 7.48051948 US gallons

radius (r) = d/2 = 4/2 = 2

Volume of a cylinder = Pi*r2*h

V = Pi*22*4 ~= 50.2654824 cubic feet * 7.48051948 gallons/cubic foot ~= 376.01 gallons