About PoolCareCalc

PoolCareCalc is a free set of pool and spa care calculators. Our goal is simple: give pool owners the exact number — how many gallons, how much chlorine, how much acid, which replacement cartridge — without the guesswork or the fluff.

What makes our tools different

• They actually work. Every calculator computes a real result from your inputs.
• They show the math. Each dosing tool has a “show the math” panel so you can see and verify the formula.
• They’re honest about limits. Chemical dosing depends on your real water chemistry; our results are estimates and we say so.

Where our numbers come from

Our dosing math uses standard, widely published pool-chemistry relationships — for example, that raising free chlorine by 1 ppm in 10,000 gallons requires about 37.9 grams of pure available chlorine. The filter-cartridge cross-reference is compiled from manufacturer and aftermarket (Pleatco, Unicel, Filbur) published charts. See the methodology page for the full set of formulas and assumptions.

How we make money

PoolCareCalc is free to use. Some links to products (such as pool cleaners, chemicals, and replacement cartridges) are affiliate links; as an Amazon Associate we earn from qualifying purchases at no extra cost to you. This never changes the calculator results or the cross-reference data. See our disclaimer for details.

A note on safety

Pool chemicals can be hazardous. Never mix chlorine products with acids, always add chemical to water (not the reverse), and follow the product label. Our tools are informational and are not a substitute for professional advice.