How many gallons of water to fill a 28 foot circumference pool?

A pool with a 52-inch wall has about 48 inches, or four feet, of water in it. The formula is (Pi)r2h, where r = 14, h = 4, and Pi = 3.14. Multiply that result by 7.5 to convert from cubic feet to gallons. That should give you about 18,500 gallons.