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Free pool care calculators

Free pool care calculators for every test reading.

Calculate salt, chlorine, pH, alkalinity, stabilizer, volume, and shock dose from the readings in your hand. Each tool gives the answer first, then the formula, source notes, and retest plan behind it.

Calculate pool salt Browse tools
No signupUse every calculator free.
Local defaultsSave gallons in your browser.
Formula visibleCheck the math before dosing.
Formula first Every calculator shows the math and assumptions behind the result.
References checked Sources include manufacturer manuals, public-health guidance, and dosing formulas.
Local defaults Optional My Pool settings stay in your browser and are never uploaded.
Retest workflow Results are planning numbers with staged additions and retesting built in.

My Pool

Save your pool once. Reuse it everywhere.

Stored only in this browser. No account, no database, no upload.

Local only
Estimate gallons

Choose by problem

Seven calculators for the most common pool math.

The pages are connected: if you do not know gallons, estimate volume first; if you already have a salt, chlorine, pH, or alkalinity reading, go straight to the right dosing calculator.

Saltwater pools

Pool Salt Calculator

Find how many pounds and bags of pool salt to add from your gallons, current salt ppm, and target ppm.

Use when Salt reading is low
You get Pounds, bags, cost, and a staged add plan
  • High-salt warning
  • 40 lb bag shopping list
  • Maintenance log
Calculate salt
Free chlorine

Pool Chlorine Calculator

Estimate how much liquid chlorine, bleach, or cal-hypo to add from pool gallons and your target free chlorine raise.

Use when Free chlorine is below target
You get Product amount, ppm raise, side-effect note, and retest plan
  • 10% and 12.5% liquid chlorine
  • Bleach and cal-hypo options
  • Startup and daily dosing
Calculate chlorine
pH adjustment

Pool pH Calculator

Estimate 31.45% muriatic acid or soda ash for staged pH adjustments based on gallons and current pH.

Use when pH is above or below target
You get Conservative dose, first-add amount, and retest guidance
  • Lower pH with muriatic acid
  • Raise pH with soda ash
  • Retest-first guidance
Adjust pH
Total alkalinity

Pool Alkalinity Calculator

Estimate baking soda to raise total alkalinity or acid process guidance when alkalinity is high.

Use when Total alkalinity is outside range
You get Baking soda pounds or acid-stage plan with pH warning
  • Raise TA with baking soda
  • Lower TA with acid and aeration
  • Links naturally to pH
Adjust alkalinity
CYA / stabilizer

Pool Stabilizer Calculator

Estimate cyanuric acid stabilizer to add from pool gallons, current CYA ppm, and target CYA ppm.

Use when CYA is below or above target
You get Dry stabilizer pounds, ounces, staged add plan, or dilution warning
  • CYA dose
  • High-stabilizer dilution
  • Links to chlorine and shock
Calculate stabilizer
Pool gallons

Pool Volume Calculator

Estimate gallons for rectangular, round, or quick surface-area pool measurements before dosing chemicals.

Use when Gallons are unknown
You get A gallons estimate you can send into the salt calculator
  • Rectangle and round pools
  • Average-depth inputs
  • Prefills salt calculator
Estimate gallons
Chlorine dose

Pool Shock Calculator

Estimate a shock dose from pool gallons, current free chlorine, target ppm, and product strength.

Use when Chlorine needs a controlled raise
You get Estimated liquid chlorine or cal-hypo amount
  • Solid or liquid products
  • PPM increase shown
  • Safety reminder
Estimate shock
STEP 1 Test first

Use a current salt or chlorine reading instead of guessing from last week.

STEP 2 Confirm gallons

Chemical doses scale with water volume, so use a reasonable pool gallons estimate.

STEP 3 Add in stages

Start below the full calculated amount when overshooting would create extra work.

STEP 4 Retest

Circulate, brush if needed, then retest before making a second adjustment.

Methodology

Built for pool math you can check.

Last updated July 2, 2026. Reviewed for formula consistency, source links, and conservative dosing language.

Formula visible

Each calculator keeps the formula or table factor near the result so the answer can be audited.

Label first

Product labels, equipment manuals, and local rules override planning estimates.

No fake credentialing

The site is an editorial tool, not a licensed pool-service diagnosis.

Retest before repeating

Calculations are staged to reduce overshooting and unnecessary chemical stacking.

Pool calculator workflow

Start with the measurement that controls the dose.

Pool chemical math usually starts with two numbers: how many gallons are in the pool and how far the current test reading is from the target. If gallons are uncertain, estimate pool volume first. If gallons are known, use the salt, chlorine, pH, alkalinity, or shock calculator for the reading you need to change.

The calculators show the result first, then keep the formula visible so the answer can be checked. Salt and chlorine use gallons and ppm change. pH and alkalinity use staged adjustment logic because those readings interact. Volume uses dimensions and average depth.