Cannot be answered with only these measurements. You need to specify what shape the pool is. Also, for a rectangular pool, the length, width and depth are needed. For a round pool, the diameter and depth are needed.
5284.62 gallons
6015.77 gallons
If 20' is the circumference, then the answer is 833.4 gallons.
70
18,000
5300 Gal
It is 30.6 cubic feet = 190.3 Imperial gallons.
13,346 gallons per vertical foot.
How many gallons of water for a 15'x30' swimming pool?
18,770 Gallons or round it up to 20,000 for calculation purposes.
A round swimming pool 12 feet across by 4 feet deep will hold 452 ft3 which converts to 3,381 gallons
'bout 1500 to 2000