21 foot what? Radius, diameter or circimference? Presumably 4 feet deep?
How many gallons will fit into a 24 foot diameter x 4 foot high round swimming pool
5284.62 gallons
There is NO way to calculate this without knowing how deep the pool is filled!
18,000
5300 Gal
It is 30.6 cubic feet = 190.3 Imperial gallons.
13,346 gallons per vertical foot.
28 is the diameter of the pool and 4 is the height (depth). 1 cubic foot is approx. 7.48 gallons. A round swimming pool is a cylinder. So: pi x (28/2)2 x 4 = 2463 cubic feet, multiply by 7.48 = 18423.24 gallons
10,408 gallons.
5,310 gallons.
There are 13,536 gallons in a 24 foot diameter pool that has 4 feet of water. Not true for a pool that is 4 feet in height. This would hold less than 4 feet of water.
7,646.4 gallons are needed.