I am happy with the length, but I can't say I wouldn't have minded 20x40 or even 18x40. 40ft length feels nice for the laps I just did I just wish it was ever so slightly wider but overall I'm very happy. We also lucked out right at 20,300 gallons so a pretty easy number to remember for chemical math. We have a half acre corner lot that's all backyard so I definitely needed a large footprint to make a dent in our backyard. I'm sure a smaller pool would be fine in a more normal 8-12k sq ft lot