Pool Chemistry Calculators — Dosing Tools & Guides
Free calculators for chlorine, pH, alkalinity, salt, CYA, shock, dilution, LSI and seasonal pool care. Start with a measured water test and choose the tool for the adjustment you actually need.
👉 Where to start
Know your pool size? Go straight to the Pool Chemistry Calculator — enter your test readings for a staged chlorine, pH and alkalinity plan.
Don't know your pool size? Start with the Pool Volume
Calculator — required for accurate dosing.
Have a saltwater pool? Check the Pool Salt Level Chart for your generator's manufacturer-specific operating range.
Need to test first? Get accurate readings before dosing — a liquid reagent test kit covers chlorine, pH, alkalinity, CYA, and calcium in one kit.
Calculate pool chemicals for any pool type
🧪 Chlorine & shock treatment
Calculate routine liquid or granular chlorine doses and one-time shock doses from measured FC. Use product/feeder guidance for tablets and the SLAM workflow for established algae.
⚖️ pH & alkalinity balance
Determine muriatic acid amounts to lower pH, or how much baking soda to raise alkalinity and stabilize water chemistry
🧂 Salt water pools
Salt pool chemical calculator for proper salt levels, plus pH and alkalinity adjustments specific to saltwater systems
♨️ Spas & hot tubs
Spa chemistry calculator with dosing adjusted for smaller water volumes and higher temperatures
Essential Calculators
Most pool owners use these weekly
Pool Volume Calculator
Find your pool size in gallons — required for all other calculations
Start herePool Chemistry Calculator
Chlorine, pH and alkalinity plan — enter readings once and stage interacting adjustments
All-in-oneChlorine Calculator
Dose to the free-chlorine target you choose
pH Calculator
Raise or lower pH for comfort and equipment protection
Shock Calculator
Calculate a one-time dose to a selected treatment target
TreatmentPool Dilution Calculator
How much water to drain to lower CYA, calcium, or salt
Problem Solving
Fix algae, high CYA, and seasonal startup
SLAM Calculator
Step-by-step algae elimination using the SLAM method
Green poolCYA / FC Calculator
Find your minimum and target chlorine for your CYA level
Pool Opening Calculator
Plan spring startup from measured chemistry with staged retesting
Pool Winterizing Calculator
Winter closing chemicals & doses for above ground and inground pools
Pool Clarifier Calculator
Scale your product-label dose by pool size — plus clarifier vs flocculant guidance
Common Adjustments
Balance your pool chemistry
Alkalinity Calculator
Balance total alkalinity to stabilize pH
Salt Calculator
Salt water pool chemical calculator for proper salt levels
Pool Salt Level Chart
Manufacturer salt ppm ranges — Hayward, Pentair & Jandy guidance, plus accurate testing
Stabilizer Calculator
Cyanuric acid to protect chlorine from sunlight
Muriatic Acid Calculator
Estimate muriatic acid dosing from pH, alkalinity, volume and acid strength
Advanced Tools
For experienced pool owners
Calcium Hardness Calculator
Prevent scaling and surface damage
Hot Tub Calculator
Spa chemistry calculator for hot tubs and smaller water volumes
LSI Calculator
Langelier Saturation Index for water balance
Chemical Cost Calculator
Estimate your annual chemical budget
Pool Filter Size Calculator
Find the right sand, cartridge, or DE filter size for your pool
Need pool supplies?
Now that you know what chemicals you need, check our recommended Pool Supplies guide — test kits, chlorine, shock, pH balancers, costs, and grocery store substitutes.
🛒 Most-used:
Pool chemistry quick tips
🧪 Test before dosing
CDC residential guidance says to test chlorine and pH at least twice per day, and more often during heavy use.
📐 Know your volume
An inaccurate pool volume carries directly into every chemical-dose calculation.
🔗 Treat CYA and FC together
If you use a CYA-based operating method, use the CYA/FC calculator rather than assuming one universal FC target.
🔄 Retest after interacting adjustments
Acid changes both pH and alkalinity. When one reading changes, recalculate the next dose from the new test result.
Common pool chemistry questions
How often should I test my pool water?
CDC residential guidance says to test chlorine concentration and pH at least twice per day and more often during heavy use. Other parameters such as total alkalinity, CYA, calcium hardness and salt usually change more slowly, but should be retested after relevant chemical additions, dilution, heavy rain or major water replacement.
What's the ideal chlorine level for a pool?
There is not one universal FC target for every pool. CDC recommends at least 1 ppm free chlorine in residential pools without CYA and at least 2 ppm when CYA or stabilized chlorine is used. Product/system guidance, local requirements and CYA-based operating methods can call for different targets.
Why does my pH keep rising?
pH drift can be influenced by total alkalinity, aeration, source water, chemical additions and carbon-dioxide loss. Test both pH and TA, then use the pH Calculator or Alkalinity Calculator rather than relying on a fixed acid dose.
Can I add all pool chemicals at once?
No. Never mix pool chemicals together or combine concentrates. Follow each product label/SDS and equipment instructions, allow the product to disperse as directed, and retest after chemistry-changing additions before calculating the next dose.
Do these calculators work for saltwater pools?
Yes. Saltwater pools still require pH, alkalinity, CYA and sanitizer management. Use the Salt Calculator for the amount of salt to add and the Pool Salt Level Chart for model-specific generator ranges.
What salt level should a saltwater pool use?
Use the operating range for your specific chlorine generator rather than one universal ppm target. For example, current Hayward and Pentair systems do not use the same ideal salinity. See the Pool Salt Level Chart for model-specific guidance.
Why can a pool turn green even when a chlorine test shows chlorine?
A chlorine reading by itself does not explain every algae problem. CYA changes chlorine activity, and poor circulation, filtration or an active algae bloom also matter. If you follow a CYA-based method, use the CYA/FC Calculator; for established algae, the SLAM Calculator documents the TFP-style treatment method.
How much muriatic acid should I add?
Acid demand depends on pool volume, current pH, total alkalinity, target pH and acid concentration. Use the Muriatic Acid Calculator, which models pH and TA together and stages larger corrections.
How many chlorine tablets does my pool need?
Tablet dosing is product- and feeder-specific because dissolution depends on tablet formulation, size, water flow, feeder setting, temperature and time. Use the tablet label and feeder instructions; the Chlorine Calculator does not pretend a slow-dissolving tablet can be converted into an exact instant ppm dose.