mming pools usually have a length-width ratio of 2:1. The standard pool sizes that are commonly found are as follows: 12 feet by 24 feet 15 feet by 36 feet 16 feet by 32 feet 20 feet by 40 feet However, it is important to note that these sizes are specifically for rectangular pools. If you are considering a geometric or freeform pool, the dimensions will not adhere to the same ratio.