Pool chemistry calculators that show their math
Work out exactly how much chlorine, acid, salt or stabilizer your pool needs. Every calculator shows its formula and worked examples, so you can check the math and understand what you're adding before it goes in the water.
Calculators
Pool volume calculator
Gallons and liters for rectangular, round, oval and kidney pools.
ChlorinePool chlorine calculator
Dose of liquid chlorine, bleach, cal-hypo, dichlor or trichlor.
CostChlorine cost calculator
Liquid vs. tablets vs. granular: monthly amount, cost and what builds up.
ChlorinePool shock calculator
The shock level for your stabilizer and how much product it takes.
BalancePool pH calculator
Muriatic acid, dry acid or soda ash dose, using your alkalinity.
BalanceTotal alkalinity calculator
Baking soda to raise it, or acid to lower it.
SaltPool salt calculator
Pounds and bags of salt for a saltwater pool.
ChlorineStabilizer (CYA) calculator
How much cyanuric acid to add, and the chlorine level it needs.
BalanceCalcium hardness calculator
Calcium chloride to add, or how much water to replace.
BalanceLSI (saturation index) calculator
Is your water corrosive, balanced or scale-forming?
WaterDrain and refill calculator
How much water to replace to lower CYA, calcium or salt.
EquipmentPool heater size calculator
BTU needed, using the US Department of Energy method.
EquipmentPump turnover calculator
Flow rate (GPM) for your turnover time.
Guides
Ideal pool chemical levels
The chart of target ranges, what each number does, and the order to fix them.
Free chlorine and stabilizer
Why your chlorine level depends on CYA, with a full table.
How to shock a pool
The right shock level, step by step, and how to know algae is gone.
Lowering pH and alkalinity
Why pH keeps rising and how to fix pH and alkalinity without overshooting.
Raising pH and alkalinity
Soda ash, baking soda, borax or aeration: which to use, with a worked example.
How to lower chlorine
Check whether it's really too high for your stabilizer, then bring it down safely.
Swimming after shocking
What to check before getting back in the pool, instead of a fixed wait.
Saltwater pool chemistry
Salt, CYA, pH and cell care for pools with a salt chlorine generator.
Cleaning a salt cell
When to clean, the acid soak step by step, and how to keep scale away.
Saltwater vs. chlorine pool
Chemistry, upkeep and costs compared, with worked numbers.
Phosphates in pool water
Why chlorine matters more, and when a remover is worth using.
Foamy pool water
Algaecide, body products and other causes, and how to clear it.
Why is my pool cloudy?
The five common causes and a test-first checklist.
How to test pool water
Strips vs. drop kits, and the readings that mislead.
Pool algae types
Green, mustard and black algae, pink slime and water mold, and how to clear each.
Strong chlorine smell?
Chloramines explained, with a calculator for the dose that clears them.
Pool stains
Metal or organic? Two spot tests, the causes, and safe removal.
Filling a pool
What to add after filling, and in what order.
Sand vs. cartridge vs. DE
How the three filter types compare, and which suits you.
How to close a pool for winter
Balancing for cold water, shocking, lowering the level and protecting the plumbing.
Pool losing water?
The bucket test, what your readings reveal, and where leaks hide.
Pool chemical safety
What never to mix, how to add chemicals, and safe storage.
How we approach this
Most pool dosing charts give one number per 10,000 gallons and stop there. But how much chlorine you need depends on your stabilizer, and how much acid moves pH depends on your alkalinity. Our calculators take those into account, use published chemistry and sources such as the CDC and the US Department of Energy, and explain their assumptions. Read our editorial policy to see how the tools are built and checked.