How to use the pool salt calculator
- Enter the pool volume in gallons. Use the pool volume calculator if you are not sure.
- Test the water with salt test strips or a digital meter and enter the current reading. A brand-new or freshly filled pool starts near 0 ppm.
- Enter the target from your salt cell manual. Most chlorine generators want about 2,700 to 3,400 ppm, and 3,200 ppm is a common target.
The pool salt formula
A gallon of water weighs 8.34 lb and 1 ppm is one pound of salt per million pounds of water. So every 1,000 ppm in a 10,000 gallon pool takes about 83 lb of salt.
How much salt for a new pool (0 to 3,200 ppm)
| Pool volume | Salt | 40 lb bags |
|---|---|---|
| 10,000 gal | 267 lb | 7 |
| 15,000 gal | 400 lb | 10 |
| 20,000 gal | 534 lb | 14 |
| 25,000 gal | 667 lb | 17 |
| 30,000 gal | 801 lb | 20 |
Worked example
A 15,000 gallon pool reads 2,400 ppm and the cell wants 3,200 ppm. The rise is 800 ppm: 800 × 15,000 × 8.34 ÷ 1,000,000 = about 100 lb, which is 2.5 bags of 40 lb salt (buy 3 and keep the rest for later top-ups). Starting a new 15,000 gallon pool from 0 ppm takes about 400 lb, or 10 bags.
Tips for adding salt
- Use pool salt. Buy salt that is at least 99% pure sodium chloride without anti-caking agents or iodine.
- Spread it in the deep end with the pump running and brush the undissolved salt toward the main drain.
- Wait 24 hours before you test again and before you switch the salt cell back on, unless your manual says otherwise.
- Salt does not evaporate. You only lose it through splash-out, backwashing and rain dilution, so top-ups are usually small.
Next step: set your free chlorine level with the pool chlorine calculator.
Frequently asked questions
How much salt do I need for a 15,000 gallon pool?
About 400 lb (10 bags of 40 lb) to go from 0 to 3,200 ppm. If the pool already reads 2,400 ppm, you need only about 100 lb.
How many bags of salt do I need for my pool?
Divide the pounds of salt by the bag weight. Each 1,000 ppm in a 10,000 gallon pool takes about 83 lb, so about two 40 lb bags.
What salt level should a saltwater pool be?
Most salt chlorine generators run best between about 2,700 and 3,400 ppm, with 3,200 ppm a common target. Check the manual for your cell.
What happens if I add too much salt to my pool?
Very high salt can make the water taste salty, trip the cell's high-salt warning and corrode metal parts. The only way to lower it is to drain part of the pool and refill with fresh water.
How long does pool salt take to dissolve?
Usually a few hours with the pump running and some brushing. Wait about 24 hours for it to mix evenly before testing again.
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Last updated October 2026.