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Pool Calculators for Volume, Chemistry & Cost
Start with your pool volume, then get chemical doses, salt, heating and running costs. Every result shows its inputs and units.
Start with your pool volume
One accurate volume unlocks every chemical dose, heater size and running-cost estimate on the site.
The hub
All pool calculators
Pick the job you need to do — volume, water chemistry, equipment sizing or running costs. Each tool shows the inputs and units behind its result.
Volume Calculator
Capacity in gallons and litres for any pool shape.
Chemical Calculator
Calculated doses for pH, alkalinity, calcium and stabilizer.
Chlorine Calculator
Daily chlorine and shock doses by pool volume.
Salt Water Calculator
Salt needed for a new fill or a top-up.
LSI Balance Calculator
Check whether water is corrosive, balanced or scaling.
Heating Calculator
Heat-up time, heater size and energy cost.
Cost Calculator
Fill, heating and monthly running costs.
Learn the why
Pool care guides
Short, practical guides that explain the measurements and chemistry behind the calculators.
How to Measure Your Pool
Measure any shape correctly — waterline, average depth, conversions and mistakes to avoid.
Pool Chemistry Basics
The five readings that matter, ideal ranges, testing order and how each chemical affects the others.
Troubleshooting Cloudy Water
Diagnose filtration, chemistry and particles in order, with a three-day clearing protocol.
How we build
Built for real pool care
No black-box results. You can see the inputs and units behind every result before you dose or buy anything.
Inputs and units are shown behind every result
No account required — start calculating immediately
Saved pools stay in your browser, not on our servers
Region-aware units and chemical ranges
Always free — no paywall or subscription
Read more about our approach on the about page.
Common questions
Pool calculator questions
Which pool calculator should I start with?
Start with the volume calculator. Every chemical dose, heater size estimate and running cost depends on how much water your pool holds. Once you have your volume, move to the chemical, chlorine or salt calculator for calculated doses.
Do I need my pool volume for every calculator?
Most dosing and sizing tools need it. The volume calculator saves your pool in your browser, and the other calculators can reuse that saved volume. If you only need a volume estimate, you can use the volume calculator on its own.
Are the calculators free?
Yes. Every calculator and guide on Pool Calculate Hub is free to use. There is no account, no paywall and no subscription.
Which units should I use?
Use the units printed on your chemical label or test kit. US products usually dose in gallons and pounds; Australian, UK, Canadian and European products usually use litres, kilograms and mg/L. The region switcher and unit toggles let you work in either system.
How accurate are the results?
The calculators use standard pool-industry formulas and constants. Results are estimates for planning, not a substitute for a test kit, product label or professional diagnosis. Re-test after 6–8 hours of circulation before adjusting again.
Are my saved pools private?
Yes. Saved pools are stored in your browser local storage on your device. They are not sent to our servers, and clearing your browser data removes them.
Do you show the formulas?
Yes. The volume formulas are documented, and every calculator shows the inputs and units behind its result. Our about page explains how the tools are built.
Still have a question? Contact us.
Ready to calculate?
Start with your volume, then follow the result straight into chlorine, salt, pH or cost.