how to calculate the gallons in a pool
How to calculate the gallons in a swimming pool To figure out how many gallons are in a swimming pool, determine the length, width, average depth and multiplier-Length * Width * Average Depth * Multiplier = Gallons Determine the Multiplier: Rectangle, square, or free-form pool: multiplier = 7.5.ow to calculate the gallons in a swimming pool To figure out how many gallons are in a swimming pool, determine the length, width, average depth and multiplier-Length * Width * Average Depth * Multiplier = Gallons Determine the Multiplier: Rectangle, square, or free-form pool: multiplier = 7.5.