Calculate Pool

Use this when someone asks how much of a pool chemical to add to go from a current to a target level: chlorine (liquid chlorine 12.5 %, bleach 10 % or 6 %, cal-hypo 65 % or 73 %, dichlor, trichlor) for free chlorine; salt for a salt chlorinator; baking soda to raise or muriatic acid to lower total alkalinity; stabilizer (cyanuric acid); calcium chloride for calcium hardness; muriatic acid to lower pH or soda ash to raise it. Levels in ppm (pH for the pH chemicals). Returns the amount in fl oz, oz or lb, a readable amount, the number of common packages, the factor used and a safety line. Not for shock targets or water-balance (LSI) questions.

chemical_dose

Use this when someone asks what size pool heater (BTU per hour) they need to raise the water a number of degrees Fahrenheit in a given time. Takes gallons, the temperature rise in °F and the hours (default 24), plus an optional buffer for surface heat loss (default 20 %, the same as the heater calculator on calculatepool.com). Returns the BTU/h required, the size with the buffer, the total BTU and the electric input of an equivalent heat pump. Not for heating cost per month or heater model recommendations.

heater_size

Use this when someone asks what size pool pump they need or what flow rate turns their pool over in a given number of hours. Takes gallons and turnover hours (default 8). Returns gallons per minute, gallons per hour, a rule-of-thumb horsepower range, the minimum sand, cartridge and DE filter area for that flow, and pipe velocities. Not for electricity cost or pump model recommendations.

pump_size

Use this when someone wants to know how many gallons (or litres, cubic feet) a swimming pool holds from its shape and size: rectangle, round, oval, Roman, Grecian, kidney, L-shape or freeform, with one depth, a shallow and a deep end, or an above-ground wall height (48, 52, 54 in). Dimensions in feet or metres. Returns gallons, litres, cubic feet, cubic metres, surface area and the formula. Use it before chemical_dose, pump_size or heater_size when only dimensions are known.

pool_volume

Use this when someone asks how many gallons a common pool size holds, e.g. a 24 ft round above-ground pool with a 52 in wall or a 16 x 32 inground pool, or wants a table of standard sizes. Returns inground rectangles (12x24 to 25x50 ft at 3.5, 4.5 and 5.5 ft average depth) and above-ground round and oval pools (12-33 ft round, 12x24 to 21x41 ft oval at 48, 52 and 54 in walls) with the factors used. For any other size or shape use pool_volume.

pool_facts