Chemistry calculator

Liquid chlorine dose

Exact active-mass planning from label strength and product density.

A pool water sample and testing kit beside clear blue pool and spa water

Your measurements

Enter known values

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Water volume (US gal)Volume unitsCurrent free chlorine (ppm)Target (ppm)Available chlorine (% by mass)Use the product label—not a marketing name.Density (g/mL)Use the label or SDS.

Calculated planning amount

979 mL full planning amount

Start with 489 mL (16.6 fl oz), then circulate and retest.

Before actingMeasure first. Follow the product label. Add chemicals separately; circulate and retest.

Formula: active chlorine mass ÷ strength ÷ density
Assumptions: Strength is available chlorine by mass; density must come from the product label or SDS. 50% staged-dose planning factor; circulate and retest before more.
Source: CDC treatment guidance · verified July 22, 2026

How to use this result

A planning quantity, not an instruction to pour.

1. Verify

Recheck volume, test reading, product strength, density or purity, and the selected target.

2. Read the label

Use the label’s application method, protective equipment, maximum dose, spacing, and re-entry directions.

3. Add separately

Never combine chemicals. Add one product at a time with circulation as directed.

4. Retest

Start with the staged amount, allow the label-directed circulation time, and measure again.