Does size matter? Well, form follows function. If your pool is for dunking (cooling), playing and floating, you don't need size.

But if you want to swim laps I think you need a MINIMUM of 36' in length. I have a 40' long pool and that's great for lapping, but my parents had a 33' foot oval and even going long point to long point it wasn't really long enough. My pool is only 16' wide, but 16x40 is just great for us, seems big enough, and we don't miss AT ALL the 20' width we had originally planned for.