Pool Chemical Dosage Calculator
Test your pool water, enter the readings, and get exact grams of chlorine, soda ash, or baking soda to add — calculated for your pool volume, not a specific product brand. Works in litres or gallons. Nothing uploaded.
Current Status
Treatment Plan
Free Chlorine
pH
Total Alkalinity
Cyanuric Acid
Dosing notes
- Never mix pool chemicals together before dissolving in water.
- Add pH/alkalinity chemicals at least 4 hours before or after chlorine shock.
- Re-test after 4–8 hours of circulation before adding more chemicals.
- Doses are based on 100% pure active ingredient. Adjust for your product's stated concentration.
Learn more: how the pool chemical doses are worked out
Chlorine
Raising free chlorine by 1 ppm means adding 1 mg of available chlorine per litre. In 10,000 L that is 10 g of available chlorine. With 65% calcium hypochlorite it takes 10 / 0.65 = 15.4 g of product. The tool uses that sum for any product strength, so 12.5% liquid works out to 80 g, shown in grams and not in millilitres.
Yakima County's chemical dosing chart lists 2.0 ounces of calcium hypochlorite per 10,000 US gallons for 1 ppm, which is about 15 g per 10,000 L. That agrees with the tool.
pH, alkalinity and stabilizer
The same chart gives 6 ounces of soda ash to raise pH by 0.2, 12 fluid ounces of 35% muriatic acid to lower it by 0.2, 1.5 pounds of baking soda to raise alkalinity by 10 ppm, and 13 ounces of cyanuric acid to raise stabilizer by 10 ppm, all per 10,000 gallons. It says the amounts are approximate and may vary with the starting pH, and that the labels give exact amounts.
Converted to 10,000 L, the tool uses 22.5 g of soda ash per 0.1 pH, 47 mL of acid per 0.1 pH, 180 g of baking soda per 10 ppm and 100 g of cyanuric acid per 10 ppm. To lower alkalinity it uses 188 mL of acid per 10 ppm, because the chart says 12 fluid ounces of acid lowers alkalinity by 5 ppm. With weaker 31.5% acid, use about 10% more.
For example, in 10,000 L, going from pH 7.8 to 7.4 takes 188 mL of acid. Raising alkalinity from 60 to 100 ppm takes 720 g of baking soda. The tool works out each change on its own. Acid for pH also lowers alkalinity, and soda ash raises it, so retest after each addition before you do the next.
Target ranges
The tool's target bands are its own: free chlorine 1 to 3 ppm, pH 7.2 to 7.6, alkalinity 80 to 120 ppm and cyanuric acid 30 to 80 ppm. Check the limits for your own pool or local health rules, which can differ. The pool type setting does not change the chlorine dose. The amounts depend only on your volume and readings.
Safety
Wait before retesting, as the page advises, and never mix chlorine products with acid or with each other. Read the product label for handling steps, and use the exact amounts there when they differ from this estimate.
FAQ
Why does the tool show different amounts than my product label?
It gives approximate doses from a chart and a product-strength sum. Labels vary by brand and strength, so use the label amount when it differs.
Why correct alkalinity before pH?
Many guides suggest it, since alkalinity affects how much pH moves when you add chemicals. The chart also shows that acid and soda ash change alkalinity as well as pH, so retest between steps.
Does the spa setting use more chlorine?
Not in this tool. The dose comes from your volume, the change in ppm and the product strength. For a spa, enter the ppm target you need.