Measuring a swimming pool is necessary for two reasons. The first is to calculate the water volume in the pool. You will use this number frequently when adding chemicals to the pool water as many of the chemicals depend on the amount of water in the pool. The second reason for measuring a pool is to determine the square feet necessary for replacing a pool liner. When taking these measurements, you will most likely need a friend to help you with the tape measure.
Measure the pool’s length and width. Take the measurements by holding the tape measure at the two points farthest from each other on the length and width of the pool.
Calculate the average depth for the pool. For example, add the shallow end figure (3 feet) with the deep end figure (9 feet). Divide by two, which will result in an average depth of six feet.
Multiply the length times width times average depth. For rectangle, square or custom-form pools, multiply the figure by 7.5 to compute total water volume in gallons; multiply round or oval pools by 5.9 to compute total water volume in gallons.