designakis.com - Swimming Pool Volume ... Knowing how much water your pool will hold is the key to having the correct water chemistry, sizing pumps, filters, and more. If you want to be able to calculate your swimming pool volume in gallons, all you have to do is follow a simple formula that is derived from your pool's shape.Olympic-size swimming pool. An Olympic-size swimming pool conforms to regulated dimensions, large enough for international competition. This type of swimming pool is used in the Olympic Games, where the race course is 50 metres (164.0 ft) in length, typically referred to as "long course", distinguishing it from "short course" which applies to competitions in pools that Pool depth & volume. Pool Volume Calculator. Here is a great tool to calculate the volume or capacity of your pool. Important! Remember to measure from the depth of the water rather than the height of your wall.Swimming pool calculators. Swimming pool calculators. Calculating the volume of a swimming pool. Converting gallons to litres. Converting litres to gallons. Adding sodium bicarbonate to increase total alkalinity.