Boneyard Tools

Pool Chlorine Dosage Calculator

Work out how much chlorine product to add to lift your pool's free chlorine by a set amount. Enter the gallons, the ppm rise you want and the product strength to get the dose in grams, ounces and pounds.

How to calculate a chlorine dose

  1. Enter your pool volume in gallons.
  2. Set the free chlorine rise you want, in ppm.
  3. Enter the product's available chlorine percent, or keep 65 for cal-hypo.
  4. Read the product needed in grams, ounces and pounds.

Examples

10,000 gallon pool, raise 2 ppm

10,000 gallons, +2 ppm, 65% cal-hypo
About 116 g of product (4.11 oz, 0.257 lb)

Frequently asked questions

How much chlorine raises free chlorine by 1 ppm?

Because 1 ppm equals 1 mg per liter, you need 1 mg of pure chlorine per liter of water. For a 10,000 gallon pool that is about 38 grams of chlorine per ppm.

What does available chlorine percent mean?

It is the share of a product that is active chlorine. Cal-hypo is about 65 percent and dichlor about 56 percent, so weaker products need a larger dose.

Why convert gallons to liters first?

Parts per million is a metric measure of milligrams per liter, so the math is cleanest in liters. The tool converts your gallons for you using 3.785412 liters per gallon.

Is this for shocking the pool too?

Yes. Shocking is just a larger ppm rise, often to 10 ppm or more. Enter the bigger target and the tool scales the product mass linearly.

Should I add all the chlorine at once?

Pre-dissolve granular products and add them gradually with the pump running. Always follow the label, and retest before swimming.

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