Pool calculator FAQ

Pool Calculate Hub is a free collection of pool calculators and practical guides. It covers volume, chlorine, pH and alkalinity, salt, LSI balance, heating and running costs, with units for the US, Australia, UK, Canada and Europe.

Start with the volume calculator, because doses and sizing depend on how much water your pool holds. Then use the chlorine calculator for sanitizer, the chemical calculator for pH and alkalinity, the salt calculator for salt systems, the heating calculator for heat-up time, and the cost calculator for running costs.

No. Every calculator runs in your browser with no signup, download or app install. Saved pools are stored in your browser on that device.

Yes. On the volume calculator you can name and save each pool. The browser remembers them on that device. Saved pools are not synced between devices, and clearing browser data removes them.

Yes. The calculators are designed for small screens, so you can enter a test reading or product strength while you are standing in the aisle. You still need a connection to load the page.

Volume supports US gallons, imperial gallons, litres and cubic metres. Doses support ounces, pounds, grams, kilograms, fluid ounces and millilitres. Temperature supports Fahrenheit and Celsius. Use the units printed on your test kit or product label.

Chemical doses, heater sizing and running costs all scale with the amount of water. A dose that is right for 10,000 gallons can be harmful in a 25,000-gallon pool. Save your volume once and reuse it across the other tools.

Labels often assume a different pool volume, target range or active-ingredient strength. Check the percentage on your product, your current reading and your target before dosing. The calculator is a planning estimate; the product label and local regulations take priority for safety.

Circulate for 6–8 hours before retesting most chemicals, and 24 hours for salt. Adjust one parameter at a time. pH affects how well chlorine works and changes the LSI balance, so retest pH and sanitizer together.

Shock dosing is currently part of the chlorine calculator, and heater sizing is part of the heating calculator. Focused shock and heater-size pages are planned so each tool can cover its topic in more depth.

The calculators use standard pool formulas and constants, but accuracy depends on your measurements and product strength. Rounded measurements, irregular shapes and partially filled pools add error. Treat the output as a planning estimate, not a diagnosis.

The tools are built from published pool formulas and product-label dosing conventions, and each page documents the inputs it uses. We do not claim medical or professional certification. If a result looks wrong, send us the inputs and the product label so we can reproduce it.

Saved pool data stays in your browser and is not sent to us. We use analytics to understand which pages are useful, and the privacy policy explains what is collected and why.

Products, units and local guidance differ. For example, free chlorine targets depend on your stabilizer level, and some regions dose in mg/L while others use ppm. The region switcher changes units and defaults, not the underlying chemistry.