Multiply all the numbers to get the volume of the pool in cubic feet. Then divide by 7.5. That assumes the water is filled to a height of four feet. Some above-ground pools have 52" walls, which allow for a water height of 48", which is four feet. The dimensions stated above in the reworded question are for an oval pool, not a round one. I suspect the original question was for a round pool with an 18' diameter and a 4.5' wall. (The slash in 4 1/2 did not show up in the question.) If that is the case, then the answer is 3.14 times 81 times 4.5 divided by 7.5.
If this is a round pool 18 feet across and you fill it with 4 feet of water, it contains 7,646 gallons of water.
How many gallons of water for a 15'x30' swimming pool?
There are 7,985.76 gallons of water in a 1799.5 cubic feet pool.
A pool this size can hold up to about 5,250 gallons of water.
A pool of this size can hold up to about 11,970 gallons of water.
This pool can hold a maximum of about 5,707.6 gallons of water.
This pool, when filled with 4.5 feet of water, will contain about 15,300 gallons of water.
600,000 gallons
48,000 gallons of water
The Shamu Close up pool is 1 million gallons
Is the pool a circle? Do you want US gallons, or Imperial gallons?
This size pool holds up to about 12,926 gallons of water.