Pool Filter Sizing Calculator
Calculate the required filter size and flow rate for your swimming pool based on pool volume, turnover rate, and filter type.
Recommended: 6–8 hrs residential, 4–6 hrs commercial
Formulas Used
Pool Volume (gal) = Length (ft) × Width (ft) × Avg Depth (ft) × 7.48052
Required Flow Rate (GPM) = Pool Volume (gal) ÷ (Turnover Time (hrs) × 60)
Minimum Filter Area (ft²) = Flow Rate (GPM) ÷ Max Flow Rate per ft²
Recommended Filter Area (ft²) = Minimum Filter Area × 1.20 (20% safety factor)
Max Flow Rates by Filter Type: Sand = 15 GPM/ft² · Cartridge = 0.375 GPM/ft² · DE = 2 GPM/ft²