About RoundPool
If you own a pool — or you’re about to build one — you’ve probably noticed the numbers never quite line up. A round pool’s volume doesn’t follow the same formula as a rectangular one. Chlorine comes as liquid, cal-hypo, dichlor, or trichlor, and a dosing chart written for one doesn’t transfer to another. A saltwater system has its own target salinity range that has nothing to do with how you’d shock a regular chlorine pool. Heater listings quote BTU/hr as if every backyard, climate, and starting water temperature were identical. Pump specs talk about “turnover rate” without ever saying how many hours a day you should actually run yours. And once the water’s in front of you, deciding whether it’s balanced, corrosive, or scaling means juggling pH, alkalinity, calcium hardness, temperature, and total dissolved solids all at once. None of it is difficult math on its own — it’s just scattered across product labels, forums, and spec sheets that were never written to work together.
RoundPool exists to put that arithmetic in one place. The Pool Volume Calculatorturns your pool’s shape and dimensions — round, rectangular, or oval — into gallons, cubic feet, and litres, since that number is the starting point every other decision depends on. The Chlorine Dosing Calculator works out how much to add to hit a target free-chlorine reading, whether you’re dosing with liquid chlorine, cal-hypo, dichlor, or trichlor. The Pool Salt Calculator tells you how much salt to add to bring a saltwater system up to its generator’s ideal salinity, in pounds, kilograms, or 40-lb bags. The Pool Heater BTU Calculator estimates the heat energy needed to raise your water by a given number of degrees, and roughly how many hours that takes at a given heater output. The Pump Turnover Calculator converts a target turnover into either the flow rate you need or the run time your current pump requires. And the Pool Water Balance Calculator runs the Langelier Saturation Index against your pH, alkalinity, calcium hardness, temperature, and TDS so you know what to adjust before anyone gets in.
Beyond the calculators, the blog and learnsections work through the reasoning behind those numbers — why turnover rate matters, what dichlor does that liquid chlorine doesn’t, how salinity and free chlorine interact in a salt system, and similar ground. Separately, the Pools & Water Museumis a set of browsable galleries on pool types and finishes, equipment and filtration, water chemistry, and the backyard and aquatic life around a pool, built from Wikipedia and Wikimedia Commons entries rather than from anything on this site’s own tools.
A few things worth being upfront about. RoundPool is an independent, advertising-supported site — it isn’t run by a pool builder, chemical manufacturer, or equipment brand, and it isn’t affiliated with any standards body or product referenced in its tools or guides. Every calculator here produces an estimate from the numbers you enter and established pool-care formulas; it’s not a substitute for testing your actual water with a proper kit, reading your product’s label, or getting advice from a pool professional, particularly where chemical handling and equipment safety are concerned. Treat the results as a solid starting point, not the final word.
Found a tool that doesn’t match your results, or have something to add? Get in touch.