Pool Liquid Chlorine Calculator (Ounces to Raise Free Chlorine)
Fluid ounces of liquid chlorine (sodium hypochlorite) to raise free chlorine by a target number of ppm, from pool volume and product strength.
Formula
Available chlorine (g) = gallons × 3.78541 L/gal × ppm (mg/L) ÷ 1,000. Product (mL) = grams ÷ (strength% ÷ 100), since trade percent is grams of available chlorine per 100 mL. Fl oz = mL ÷ 29.5735.
Worked example
Inputs: Pool volume = 15000 gal; Raise free chlorine by = 3 ppm; Product strength (trade %, on the jug) = 12.5 %.
| Available chlorine g | 170.3 |
|---|---|
| Product fl oz | 46.1 |
| Product gallons | 0.36 |
| Product ml | 1,363 |
FAQ
How much 12.5% chlorine raises 10,000 gallons by 1 ppm?
10,000 × 3.78541 ÷ 1,000 = 37.9 g; 37.9 ÷ 0.125 = 303 mL, about 10.2 fl oz.
Can I use household bleach?
Yes if it is plain, unscented bleach, but its label states sodium hypochlorite by weight rather than trade percent, so treat the result as approximate and retest.
What free chlorine level should I keep?
Follow your local health code or pool-care guidance, which ties it to your cyanuric acid level; this tool only computes the dose.
Sources
- NIST: 1 US gallon = 231 cubic inches (7.48052 gal per cubic foot)
- Geometry (volume/area formulas); no external constant needed
Related
- Pool Salt Calculator (Pounds of Salt for a Saltwater Pool)
- Pool Volume Calculator: Rectangular (Gallons)
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Last reviewed 2026-10-13.