Enter your pool volume, current and target free chlorine, and the product strength to see how much liquid chlorine or bleach to add.
About the pool chlorine dose calculator
The pool chlorine dose calculator turns four numbers into one clear answer: how much liquid chlorine or bleach to add to raise your pool's free chlorine to a target level. Enter your pool volume in gallons, your current free chlorine in parts per million, the free chlorine you want to reach, and the strength of the product you are using, such as 6 percent household bleach or 12.5 percent liquid pool chlorine. The tool returns the fluid ounces, cups, and gallons of product to add, along with a short pool chemical safety note.
This is an educational estimate for liquid chlorine and bleach dosing, not professional, medical, or safety advice. It covers liquid products only, because the result is a liquid volume; granular or cal-hypo shock is dosed by weight, not volume, and is not covered here. Always follow your product label, handle pool chemicals safely, and confirm your free chlorine and pH with a test kit. The tool runs entirely in your browser. It stores no addresses, service requests, photos, water-test data, or contact details, and the numbers you enter are used only to compute a local dose and are never sent anywhere.
How to use
- Enter your pool volume in gallons. A rough estimate is fine; larger pools need more product.
- Enter your current free chlorine in ppm, measured with a test strip or kit.
- Enter the target free chlorine in ppm you want to reach.
- Pick the product strength, such as 6 percent bleach or 12.5 percent liquid pool chlorine, or enter a custom percent from the label.
- Read the dose: the fluid ounces, cups, and gallons to add. Re-test and wait until free chlorine is back in the recommended range before swimming.
Worked examples
15,000 gallons, raise 1 to 3 ppm with 12.5%: about 30.7 fl oz
Raising free chlorine by 2 ppm in a 15,000 gallon pool with 12.5 percent liquid chlorine takes roughly 30.7 fluid ounces, a little under a quart.
10,000 gallons, raise 0 to 3 ppm with 6% bleach: about 64 fl oz
A weaker product means more volume. Reaching 3 ppm from zero in 10,000 gallons with 6 percent household bleach takes about 64 fluid ounces, or roughly half a gallon.
Already at target: no dose
If your current free chlorine is already at or above your target, the tool tells you no chlorine is needed to reach it.
Frequently asked questions
- How much chlorine does it take to raise free chlorine by 1 ppm?
- It depends on pool volume and product strength. As a reference, raising free chlorine by 1 ppm in 10,000 gallons takes about 10.2 fluid ounces of 12.5 percent liquid pool chlorine, or about twice that with 6 percent household bleach. The calculator scales this to your exact pool size, current level, target, and product strength.
- What product strengths can I use?
- The presets cover common liquid products: 6 percent regular bleach, 7.5 percent concentrated bleach, and 10 or 12.5 percent liquid pool chlorine. You can also enter a custom percent from your product label. The percent is the available chlorine listed on the container.
- Does it work for granular shock or cal-hypo?
- No. Granular and cal-hypo shock are dosed by weight, not by liquid volume, so mixing them into a fluid-ounce result would be inaccurate. This tool covers liquid chlorine and bleach only. For granular products, follow the dosing chart on the label.
- Is this professional or safety advice?
- No. This is a free educational estimate of a liquid chlorine dose. It is not professional water-treatment, medical, or safety advice. Always follow your product label, add chemical to water rather than water to chemical, never mix chlorine products, and confirm chlorine and pH with a test kit.
- What free chlorine level should I target?
- CDC Healthy Swimming points to keeping free chlorine and pH in the recommended ranges for residential pools, commonly around 1 to 3 ppm free chlorine with pH near 7.2 to 7.8. Your ideal target can vary with stabilizer (cyanuric acid) level and use, so check your test kit guidance. This tool estimates the dose to reach the target you choose.
- Does it store anything I enter?
- No. The calculator runs entirely in your browser. The pool size and chlorine numbers you enter are used only to compute a local dose. Nothing is stored or sent to a server, and no addresses, service requests, photos, water-test data, or contact details are collected.
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