Pool Salt Calculator
Find out exactly how much salt to add to your pool to reach the ideal salinity for your salt chlorinator — in seconds, for free.
How to use this pool salt calculator
Enter your pool volume in gallons or liters. Not sure? Check your pool builder’s paperwork, or use the formula: length × width × average depth × 7.5 for rectangular pools.
Test your water with a salt test strip or digital salinity meter and enter your current reading in ppm. Enter 0 if this is a new pool or you have never added salt before.
Select your salt chlorinator brand. Each system has a slightly different ideal range — the calculator pre-fills the manufacturer’s recommended target automatically.
Choose your bag size and click Calculate. You’ll get the exact pounds needed, how many bags to buy, the weight in kg, and the resulting ppm after adding salt.
Add the salt by broadcasting it around the pool perimeter with the pump running. Let it circulate for 24 hours, then retest before turning the chlorinator back on.
What salt level does a pool need?
Salt chlorine generators work by passing a low-voltage current through salt water to produce chlorine through electrolysis. For this to work safely and efficiently, pool water must maintain a salinity between 2,700 and 3,500 ppm — depending on the brand.
At those levels, the water feels comfortable — similar to a human teardrop and about one-tenth the salinity of ocean water. Too little salt and the cell shuts down or underproduces chlorine. Too much can corrode metal fittings, damage the cell, and leave a salty taste.
where 8.34 = weight of one US gallon of water in pounds
Salt does not evaporate — once added, it stays until you drain the pool, backwash, or heavy rain dilutes it. That’s why retesting every 2–4 weeks is important, especially after significant rainfall.
How much salt for common pool sizes?
Estimates from 0 ppm to 3,200 ppm (Hayward standard). Use the calculator above for your exact amount.
Salt level recommendations by chlorinator brand
| Brand / System | Ideal range (ppm) | Best target | Shutdown below |
|---|---|---|---|
| Hayward AquaRite | 2,700 – 3,400 | 3,200 ppm | 2,500 ppm |
| Pentair IntelliChlor | 2,700 – 3,400 | 3,000 ppm | 2,600 ppm |
| Jandy TruClear / AquaLink | 3,000 – 3,800 | 3,500 ppm | 2,800 ppm |
| Zodiac / Fluidra | 3,000 – 4,000 | 3,500 ppm | 2,700 ppm |
| CircuPool / generic | 2,500 – 3,500 | 3,000 ppm | 2,000 ppm |
| Ocean water (reference) | ~35,000 | — | — |
Always verify the exact range in your owner’s manual — firmware updates sometimes change these thresholds.
What type of salt should you use in a pool?
Use food-grade sodium chloride (NaCl) that is at least 99.8% pure. The most commonly available options are:
- Pool salt — the most convenient option, sold in 40 lb bags at pool supply stores, already sized and labeled for pools.
- Solar salt — slightly coarser crystals but same purity. Dissolves a bit slower. Often cheaper at hardware stores.
- Water softener salt — works well if labeled 99.8%+ pure NaCl without anti-caking additives.
Avoid: rock salt (impurities), iodized table salt, and any salt containing yellow prussiate of soda (YPS), which can stain pool surfaces blue-green.