How do you calculate how many gallons are in a pool?

To determine the volume of water in a pool, the most accurate method involves calculating the surface area and then multiplying it by the average depth. The formula divides the calculation into two parts: length times width gives the surface area of the pool, while using the average depth ensures that any variation in pool depth is accounted for.

The multiplication by 7.5 converts cubic feet to gallons, as there are 7.48 gallons in a cubic foot. This method is particularly effective for rectangular pools, where the pool's shape allows a straightforward calculation. For pools with varying depths, using the average depth provides a more realistic estimate of the actual volume of water they hold.

This method is preferable to simply multiplying depth by 7.5 or adding depth directly to the length and width before conversion, as those do not take into account the pool's total volume properly. Thus, using the formula from the correct choice accurately reflects the amount of water in the pool.