Chlorine Dosage Calculator
Calculate the exact amount of chlorine needed to reach your target sanitization levels.
10% (Liquid Bleach)
12.5% (Liquid Shock)
56% (Sodium Dichlor)
65% (Cal-Hypo)
73% (Cal-Hypo Pro)
90% (Trichlor Tabs)
You need to add:
How to Calculate Chlorine Dosage
Maintaining the correct chlorine level (typically 1.0 to 3.0 ppm) is essential for keeping pool water safe and clear. To calculate the dosage, you must know your pool's total volume, your current free chlorine level, and the concentration of the chemical product you are using.
The math behind chlorine dosage relies on the principle that 1.33 ounces of 100% pure chlorine will raise 10,000 gallons of water by 1 ppm (parts per million). Since most pool chemicals are not 100% pure chlorine, we adjust the calculation based on the product's strength.
Chlorine Dosage Formula
The standard formula used by this calculator is:
Dosage (oz) = [(Volume / 10,000) * (Target ppm – Current ppm) * 1.33] / (Strength % / 100)
Common Chlorine Concentrations
| Product Type | Typical Strength | Form |
|---|---|---|
| Liquid Chlorine/Shock | 10% – 12.5% | Liquid |
| Calcium Hypochlorite (Cal-Hypo) | 65% – 73% | Granular |
| Sodium Dichlor | 56% | Granular |
| Trichlor | 90% | Tablets |
Practical Examples
Example 1: You have a 15,000-gallon pool. Your current chlorine is 0.5 ppm, and you want to reach 3.0 ppm using 12.5% liquid shock.
- Volume Factor: 1.5 (15,000 / 10,000)
- Required Increase: 2.5 ppm (3.0 – 0.5)
- Calculation: (1.5 * 2.5 * 1.33) / 0.125 = 39.9 ounces.
Safety Tips for Adding Chlorine
- Always add chemicals to water, never water to chemicals, to avoid dangerous splashes or reactions.
- Run the pool pump for at least 2-4 hours after adding chemicals to ensure proper distribution.
- Wait at least 30 minutes (or as directed by the product label) before swimming after adding liquid chlorine.
- Store chlorine in a cool, dry, well-ventilated area away from other chemicals like muriatic acid.