Get your pool water right, without the guesswork
Free calculators for pool volume, chlorine, and water care. Every tool is free, instant, and works right in your browser — nothing is stored or sent anywhere.
Pool turned green? Start here
The fix everyone talks about is the SLAM method (Shock Level And Maintain): raise chlorine to a level based on your stabilizer and hold it until the algae is dead. Our green pool calculator gives you your exact shock level, the doses, and the day-by-day plan in plain english.
Green Pool Fix Calculator →The Basics
Pool Chemistry 101The 7 test numbers explained once — pool care stops being mysterious.Saltwater vs. ChlorineSalt pools make their own chlorine — here's the real trade-off.Water Test Report CardType in your test results, get a report card and a fix-it order.Pool Testing Schedule BuilderWhat to test and how often, tuned to your pool. Printable.Pool Cheat Sheet MakerPrint a card with your pool's numbers for the equipment pad.Can I Swim Yet?Added chemicals? Find out exactly when it's safe to swim.Kidney Pool Volume CalculatorGallons for kidney & freeform pools — the shape the standard calc skips.Pool Volume CalculatorHow many gallons your pool holds — the number everything else needs.Intex Pool Chemical CalculatorHow much chlorine for your Intex pool, by size — and what to skip.Above Ground Pool GallonsGallons for every standard above-ground size, wall height handled.New Pool Owner Starter KitThe honest first shopping list, sized to your pool.
Water Chemistry
Cyanuric AcidSunscreen for your chlorine — and why more is a costly mistake.Chemistry Order of OperationsFix the numbers in this order and each one finally holds.LSI / CSI CalculatorIs your water scaling or corrosive? The pro-grade balance index.Phosphate Remover CalculatorDose by your ppb reading — including the honest 'you don't need it' verdict.Algaecide CalculatorPolyquat doses for prevention and openings — and what algaecide can't fix.Pool Chlorine CalculatorExact liquid chlorine dose to hit your target FC level.Salt Cell % CalculatorThe salt cell % that matches your pool's daily chlorine demand.Pool Salt CalculatorPounds of salt to reach your SWG's target ppm.Pool Shock CalculatorThe right shock dose from your combined chlorine reading.CYA (Stabilizer) CalculatorStabilizer dose to stop sunlight burning off your chlorine.Pool Alkalinity CalculatorBaking soda dose to raise total alkalinity.pH Increaser CalculatorThe soda ash dose to raise pH, in safe steps you retest between.Muriatic Acid CalculatorAcid dose to bring high alkalinity and pH back down.Calcium Hardness CalculatorCalcium chloride dose to protect plaster and equipment.Pool Borate CalculatorBorax + acid doses for the 30–50 ppm borate upgrade.
Hot Tubs & Spas
Hot Tub Chemical CalculatorEvery spa reading graded at once, with teaspoon doses and a drain date.Hot Tub Volume CalculatorYour spa's real gallons — seats lie, tape measures don't.Hot Tub Shock CalculatorSpa shock doses by the gram, chlorine or non-chlorine.Hot Tub Bromine CalculatorBromine granule doses in teaspoons, plus the fresh-fill startup routine.Hot Tub Chlorine CalculatorSpa-sized chlorine doses in teaspoons — small water, exact math.
Fix a Problem
Why Your Pool Loses ChlorineChlorine won't hold? The four causes and how to spot yours.Rain Effect CalculatorWhat N inches of rain just did to your water chemistry.Pool Evaporation CalculatorIs that water loss evaporation — or a leak?Drain & Refill PlannerHow much water to swap to fix a too-high level, and the cost.Pool Stain IdentifierIdentify the stain (metal, organic, scale) before buying anything.Cloudy Pool Water FixerCloudy water? Three questions, likely cause, exact fix.Overnight Chlorine Loss TestDusk vs dawn chlorine readings: the early algae detector.Green Pool Fix CalculatorPool turned green? Get the exact chlorine plan to fix it.
Costs & Equipment
Salt vs Chlorine Cost CalculatorDoes converting to salt water actually save money? The payback math.Salt Cell Replacement CalculatorWhen your salt cell will die, and what to budget for it.Variable Speed Pump SavingsWhat switching to a variable speed pump saves you per year.Pool Liner Size CalculatorMeasure your pool, get the exact liner spec — overlap, beaded, or unibead.LED Pool Light SavingsWhat the pool light really costs, and how fast LED pays for itself.Cartridge Filter CalculatorThe cartridge sqft your pool needs and the PSI that says clean it.DE Powder CalculatorDE pounds and scoops for your filter, fresh or recharge.Pool Filter Sand CalculatorPounds of sand for your filter size, and when to swap it.Pool Pump Size CalculatorThe GPM and pump size your pool actually needs (smaller than you think).Pool Cleaner PickerFour questions, one honest answer: which cleaner class fits your pool.Robot Cleaner Payback CalculatorIs the robot worth it vs your Saturday vacuuming hours?Pool Pump Run Time CalculatorTurnover hours and what your pump costs to run.Pool Cover Savings CalculatorWhat a cover saves you per season, and its payback time.Solar Pool Heater SizingHow many solar panels your pool needs, and the payback vs gas.Pool Heater Size CalculatorThe BTU size your pool actually needs, gas or heat pump.Pool Heating Cost CalculatorWhat raising your water temperature actually costs.Pool Service vs DIY CalculatorWeekly service vs doing it yourself: the honest premium.Pool Cost of OwnershipThe honest per-year cost of owning a pool, itemized.Pool Loan vs Cash CalculatorFinance or pay cash? The honest interest-vs-opportunity-cost math.Pool Affordability CalculatorFrom a monthly payment to the pool price (and upkeep) you can afford.Pool Financing CalculatorPool loan payments and the true all-in cost of buying a pool.Pool Water Delivery CalculatorTruckloads, delivery cost, and the honest hose comparison.Pool Fill Cost CalculatorWhat filling (or refilling) your pool costs, and how long it takes.
Seasonal & Events
Is the Water Warm Enough?Your water temp, honestly rated for kids, adults, and polar bears.Winter Cover Size CalculatorThe cover size to buy, overlap included, plus the hold-down hardware.Pool Closing Chemical KitYour winterizing chemicals, sized to your pool.Pool Opening Checklist GeneratorYour opening steps + a shopping list sized to your pool.Pool Party CalculatorThe chlorine plan for before and after a pool party.
Why these calculators?
Pool chemistry questions always come up poolside: the water's cloudy, the test strip says chlorine is low, and the bag of chemicals gives doses per 10,000 gallons you've never calculated. PoolCareKit answers each of those in under a minute — with the formula shown and doses in real-world units — so you add the right amount the first time.