🧂Pool Salt Calculator
Find how many pounds and 40 lb bags of salt your saltwater pool needs.
Your pool
Not sure of your volume? Use the pool volume calculator.
Add about
450 lb
12 bags of 40 lb to go from 500 to 3,200 ppm
lb salt
450
40 lb bags
12
ppm raise
2,700
🛒 Shopping list
- Pool salt (40 lb bags)12 bags
Add salt gradually around the shallow end with the pump running, and wait 24 hours before retesting. Check your salt cell's recommended range.
How it works
Pounds = (target ppm − current ppm) × gallons × 8.34 ÷ 1,000,000. Bags = pounds ÷ 40. Most salt cells like about 3,200 ppm.
Worked example
A 20,000 gallon pool going from 500 to 3,200 ppm: 2,700 × 20,000 × 8.34 ÷ 1,000,000 = 450 lb, or 12 bags of 40 lb.
Questions people ask
Most systems want 2,700–3,400 ppm; check your cell's manual.
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Last updated October 8, 2026. These results are friendly estimates to help you plan — always double-check before buying or making big decisions.