I have an Intex 18' circular pool. Leslies calculated my gallonage at 8500, which I thought was high. I went to this calculator, and got 7600 gallons (http://www.oceanmagic.net/calculating_pool_capacity.htm).
I still thought that was high, so I checked Intex, and they say 5400 (http://www.intexcorp.com/easy18x48.htm).
I am guessing Intex is probably closest to right.... but why such a great variation? That is over 50%.... and I know my pool does not vary from 12 to 18 feet in diameter!