Pool Salt Calculator
Size sodium chloride from pool gallons and your current versus target ppm. Use a preset generator target or type your own, then round up to real bag weights.
Formula example
For 10,000 gal at 0 ppm rising to 3,200 ppm, salt weight is volume × 8.345 lb/gal × Δppm ÷ 1,000,000. That is 267.0 lb—7 bags at 40 lb each.
FAQ
What does the default 10,000 gal job need?
At 0 ppm rising to 3,200 ppm with 40 lb bags, the formula gives 267.0 lb of salt—seven bags. That is test case A1 in our engine suite.
What happens when I arrive from the pool volume page?
The URL carries g=18240 from the 16×32 ft example pool. At 0 ppm to 3,200 ppm that is 487.1 lb and 13 bags of 40 lb salt.
How is partial drain-down calculated?
When the target is below current ppm, replacement gallons = volume × (current − target) ÷ current. At 4,000 ppm down to 3,200 ppm on 10,000 gal, that is 2,000 gal—20% of the pool.
Does this set chlorine or stabilizer?
No. It only estimates salt pounds, bags, or replacement water. Wait on new plaster per the surface manufacturer, broadcast salt on the water with the pump running, and keep salt out of skimmers.
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By Home Yard Calc Editorial Team · Sources listed on the methodology page · Last updated October 26, 2026
Estimates only. Densities, coverage and salt targets vary by product, moisture and manufacturer. Confirm with your supplier or equipment manual. Not a substitute for professional design, soil engineering or pool service.