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Pool care calculators

Pick the tool for today’s pool reading.

Use these calculators when you have a test result in hand and need a practical next step: salt, chlorine, pH, alkalinity, gallons, pump flow, heating cost, or a shock dose.

Quick triage

What changed since the last test?

Salt ppm is below your equipment range Calculate pounds of salt, bags to buy, and a staged add plan. You are not sure how many gallons the pool holds Estimate volume before using salt, chlorine, or other chemical dosing guides. Pump size or runtime is uncertain Estimate required GPM from gallons and turnover time before comparing equipment. You want to estimate pool heating cost Estimate heat-up cost from gallons, temperature rise, heater type, and energy price. Free chlorine needs a controlled raise Estimate liquid chlorine or cal-hypo amount from your target ppm increase. pH is drifting high or low Estimate a staged pH adjustment with muriatic acid or soda ash. CYA or stabilizer is low or too high Calculate dry stabilizer or dilution when CYA is already above target.
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

Calculator library

Fast answers with the formula still visible.

Each calculator is designed to answer first, then explain assumptions, safety limits, and when to retest. The goal is fewer guesses and fewer overcorrections.

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
Pump flow planning

Pool Pump Size Calculator

Estimate required GPM from pool gallons and turnover time, then compare the flow to filter limits and pump curve planning.

Use when Pump size or runtime is uncertain
You get Required GPM, turnover estimate, filter-limit warning, and sizing boundaries
  • GPM from turnover
  • Filter max-flow check
  • Pump curve reminder
Estimate pump flow
Heat-up cost

Pool Heating Cost Calculator

Estimate the cost to heat a swimming pool from gallons, temperature rise, heater type, energy price, and efficiency or COP.

Use when You want to heat the pool
You get BTU needed, runtime, fuel use, heat-up cost, and weather caveats
  • Heat pump, gas, propane, electric
  • Formula-visible BTU math
  • Not an exact monthly bill
Estimate heating cost
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

Maintenance workflow

A calculator result is a starting point, not a substitute for retesting.

Pool chemistry changes with rain, splash-out, refill water, sunlight, bather load, and equipment runtime. The safest workflow is to test, calculate, add conservatively, circulate, and test again before making another adjustment.

For saltwater pools

Use the salt calculator when ppm is below your chlorine generator range. If ppm is already high, dilution is usually the correction.

For chemical dosing

Use the volume calculator before dosing if gallons are uncertain. Average depth is usually better than deepest depth.

For shock treatments

Use current and target free chlorine. Always follow product labels and wait for safe test results before swimming.

For record keeping

Save readings and calculator results so your next adjustment has context.

Reference charts

Quick chart checks before you calculate.

Use reference charts for common pool sizes and planning values, then open the matching calculator when your test reading, product strength, or target range differs.

Salt reference

Pool Salt Chart: Pounds of Salt by Pool Size Use this pool salt chart to estimate pounds of salt for common swimming pool sizes and ppm increases. It uses the same gallons x ppm x 0.00000834 formula as the pool salt calculator.

Chlorine reference

Chlorine Dosing Chart for 10% Liquid Chlorine Use this chlorine dosing chart to estimate gallons of 10% liquid chlorine for common pool sizes and free chlorine ppm increases. It is a planning chart, not a product label replacement.

CYA reference

FC/CYA Chart for Pool Chlorine Planning Use this FC/CYA chart as planning context for how cyanuric acid changes free chlorine targets. It supports the chlorine, stabilizer, and shock calculators.

Volume reference

Pool Volume Chart: Common Pool Sizes in Gallons Use this pool volume chart to estimate gallons for common round and rectangular pools. It uses cubic feet x 7.48 gallons and should be checked with the volume calculator for custom shapes.

How to choose

Start with the number you trust least.

If gallons are uncertain, start with the volume calculator before using any chemical dose. If gallons are known but a test reading is low, go straight to the salt or shock calculator. If a reading is high, pause before adding anything and look for a dilution or retesting step instead.

This order keeps pool care practical: estimate the water volume, calculate one adjustment, add conservatively, circulate, and retest. It also makes the calculator output easier to audit because each page shows the formula and the assumptions behind the answer.

Why these tools are separate

Each calculator answers one job cleanly.

A single mega calculator can become confusing because pool owners often arrive with one immediate question: how much salt, how many gallons, or how much shock. Separate calculators keep the inputs short and make the assumptions easier to audit. The hub connects them when one answer depends on another, especially when gallons are unknown.

The library will expand around the same rule: each page should solve one calculation clearly, show the formula, explain when not to add chemicals, and link to the next calculator only when the workflow naturally requires it.

That keeps the site useful for repeat visits: a pool owner can return with one test result, calculate the next measured step, and move on without reading through unrelated chemical advice.

Worked answers

Common gallon-size answers with the math shown.

These answer pages use fixed assumptions for common pool sizes, then link back to the calculator when your readings differ.

salt

How much salt for a 10,000 gallon pool? For a 10,000 gallon pool, raising salt from 2200 ppm to 3200 ppm takes about 83 lb of pool salt, or 3 40 lb bags.

salt

How much salt for a 15,000 gallon pool? For a 15,000 gallon pool, raising salt from 2200 ppm to 3200 ppm takes about 125 lb of pool salt, or 4 40 lb bags.

salt

How much salt for a 20,000 gallon pool? For a 20,000 gallon pool, raising salt from 2200 ppm to 3200 ppm takes about 167 lb of pool salt, or 5 40 lb bags.

salt

How much salt for a 25,000 gallon pool? For a 25,000 gallon pool, raising salt from 2200 ppm to 3200 ppm takes about 209 lb of pool salt, or 6 40 lb bags.

salt

How much salt for a 30,000 gallon pool? For a 30,000 gallon pool, raising salt from 2200 ppm to 3200 ppm takes about 250 lb of pool salt, or 7 40 lb bags.

chlorine

How much chlorine for a 10,000 gallon pool? For a 10,000 gallon pool, raising free chlorine from 1 ppm to 4 ppm takes about 0.3 gal of 10% liquid chlorine.
Browse all answers

Troubleshooting help

When the water symptom comes before the number.

Start with a test-first checklist, then use the calculator that matches the reading instead of adding chemicals from a guess.

Troubleshooting

Green Pool Water: What to Test Before You Shock A practical green pool water checklist for testing chlorine, pH, CYA, and pool volume before using a shock calculator or adding more chemicals.

Stabilizer help

High CYA in Pool Water: What Changes Next High CYA help for pool owners: confirm the stabilizer reading, understand why dilution is often needed, and use calculators before making another correction.

Chlorine help

Low Chlorine in Pool Water: What to Check Before Dosing Low pool chlorine help that checks gallons, CYA, sunlight, algae demand, and product strength before using a chlorine calculator.

pH help

Pool pH Keeps Rising: What to Check First A pool pH keeps rising checklist for total alkalinity, aeration, saltwater pools, new plaster, and staged acid adjustments.

Cloudy water help

Cloudy Pool Water: What to Test Before You Add More A cloudy pool water checklist for chlorine, pH, alkalinity, stabilizer, filtration, circulation, and shock planning before adding more chemicals.

Pool calculator FAQ

How to use pool math without overcorrecting.

These answers explain when to start with gallons, when to use a dosing calculator, and why retesting matters more than chasing every number at once.

Which pool calculator should I use first?

Use the volume calculator first if you are unsure about gallons. If gallons are known, use the salt calculator for salt ppm changes or the shock calculator for free chlorine changes.

Are these pool calculators exact?

No. They are planning estimates based on standard pool math. Test accuracy, pool volume uncertainty, product strength, and water conditions can all change the real result.

Can I make several chemical changes at once?

It is usually safer to make one planned adjustment, circulate, and retest before stacking more changes. This reduces overcorrection and makes the result easier to interpret.

Do the calculators replace product labels?

No. Use the calculator to plan the amount, then follow the pool equipment manual, chemical label directions, and local rules for handling, dosing, and draining.

Why do the calculators ask for pool gallons so often?

Most dose estimates scale directly with water volume. Saving a reliable gallons estimate in My Pool keeps salt, chlorine, stabilizer, and alkalinity calculations consistent across visits.

What should I do when a reading is above target?

Do not look for an add-more chemical answer first. High salt, high CYA, and some high hardness situations usually need confirmation, dilution planning, or professional guidance rather than another dose.