My pool is oval, 36' x 18', 8.5' in the deep end, 3.5' deep in the shallow end. I used this calculator to calculate the volume.
It gives me 22843.33 gallons which I used in the pool calculator. However the pool has very little shallow end, and quickly gets deep because there is a diving board. The pool calculator always told me I needed less chemicals that I really needed. I think the pool volume is higher than what the calculator says. I think it is closer to 27000 gallons, based on an average depth of 7 feet. I have put that number into the pool chemical calculator and will see how accurate that is. I also changed the info in my signature, listing the pool as 27000 gallons.
Does this seem reasonable? Is there any more accurate and flexible pool water volume calculator you know of?