For years I have wanted to do a precise calculation of the gallon size of my pool. I've used many online calculators and have gotten about as many different estimates as there are calculators out there. The answer doesn't matter that much, I just really wanted to figure it out, do the math, and let that section of my brain get a little excersize.
I found an old schematic of my pool with dimensions, which makes it pretty easy. Yes, the pool is not going to match the schematic exactly, and none of the sides are perfectly straight, and none of the corners are truly square.
The following calculations assume 36" of water fill in the shallow end.
Whew. Roughly 29,000 gallons.
Furthermore, I calculated each inch of fill adds about 494 gallons. I always wondered about that.