Pool Chlorine Dosage Calculator

About this calculator

Raising a pool’s free chlorine to a target level is a mass-balance calculation: the chlorine deficit (target ppm minus current ppm) multiplied by the pool’s volume gives the total mass of available chlorine needed, and dividing that by the chosen product’s percent available chlorine converts it into the actual amount of product to add — whether that’s liquid chlorine (typically 10–12.5% sodium hypochlorite), calcium hypochlorite (around 65–73% available chlorine), or a dichlor/trichlor product with its own labeled strength.

Because different chlorine products have very different concentrations and some also affect pH or add cyanuric acid stabilizer, pool operators and Certified Pool Operators (CPOs) need this conversion to avoid under- or over-chlorinating, which can mean anything from ineffective sanitation to bather irritation and equipment damage. Enter your pool volume, current and target chlorine levels, and your product’s strength to get the dose.