Free Pool Calculators That Show Their Math
Six calculators for pool owners: volume, salt, chlorine, chemical balancing, evaporation, and what it really costs to heat your pool in your state. Every tool explains its formula, so you can trust the number it gives you.
Pool Volume Calculator
Work out how many gallons your pool holds from its shape and depth.
Pool Salt Calculator
How much salt to add to reach your salt water generator's target level.
Pool Chlorine Calculator
Liquid chlorine, cal-hypo, or dichlor needed to hit your target free chlorine.
Pool Chemical Calculator
Doses for pH, total alkalinity, and cyanuric acid adjustments.
Pool Evaporation Calculator
Estimate how much water your pool loses to evaporation per day and week.
Pool Heating Cost Calculator
Monthly cost to heat your pool by state, comparing gas, heat pump, electric, and propane.
Why these calculators?
Most pool calculators online are either sales tools built by equipment brands or bare input boxes with no explanation. Pool Calc Lab takes a different approach: every calculator on this site shows the formula it uses, walks through a worked example, and cites where its constants come from, EIA energy rates for the heating calculator, standard industry dosing factors for the chemistry tools.
Start with the pool volume calculator, because every other number, salt, chlorine, and heating cost included, depends on knowing how many gallons your pool holds. Then use the salt calculator or chlorine calculator to keep your water balanced, and the heating cost calculator to see what extending your swim season actually costs where you live.