Pool Salt Calculator

How pool salt dosing is calculated

Salt chlorine generators need a minimum level of dissolved salt in the water, typically in the 2,700-3,400 ppm range depending on the manufacturer, to produce chlorine efficiently. The amount of salt needed to raise your pool by a given number of ppm follows a simple rule used across the pool industry: pounds of salt = (target ppm − current ppm) × gallons ÷ 120,000.

That constant comes from the fact that one pound of salt dissolved in 10,000 gallons of water raises the concentration by about 12 ppm, which rearranges to the 120,000 figure used here. It is an approximation that assumes the salt fully dissolves and mixes evenly, which normal pool circulation achieves within a day or so.

Your current salt level is best measured with a digital salt test kit or test strips, though most salt chlorine generators also display an estimated ppm reading on their control panel -- use whichever reading you trust most, and re-test after adding salt and letting it circulate for 24 hours before adding more.

Where these numbers come from

The formulas and default values in this calculator are based on:

• standard saltwater pool chemistry dosing rule (1 lb of salt per 10,000 gallons raises salinity by approximately 12 ppm, equivalent to gallons/120,000 lbs per 1 ppm change), consistent with guidance published by major salt chlorine generator manufacturers including Hayward, Pentair and Intex

These are planning estimates. Test your actual water, follow product labels, and check your equipment manufacturer's guidance before you buy or dose chemicals.