How many gallons of water fill an 18 x 36 swimming pool?

mine is the same size as long as its 3 feet deep to 8 feet deep then the exactly 26730 gallons i figured that out today because we over shocked our pool by 4 times

Assuming you are referring to an 18 foot by 3 foot (36 inches) circular pool, the formula would be PIE x radius x radius x depth = cubic feet, then cubic feet x gallons per cubic foot. So here is the answer.... 3.14 x 9 x 9 x 3 = 763.02 cubic feet, then 763.02 x 7.48 (gallons per cubic foot), = 5707.39 gallons.

Diameter = total length across

Radius = half of diameter

Cubic foot = 1' x 1' x 1'

7.48 = gallons per cubic foot