Sawhorse Calc

Pool salt calculator

Enter your pool's gallons, your current salt reading and the level you want. You get the pounds of salt to add and how many bags to buy.

Pool and salt readings

Starting figures are typical. Type the ones on your product or quote if you have them.

Cost (optional)

87.6 lb of salt

Raise salt by
700 ppm
In kilograms
39.7
Bags
3

How to work it out

  1. Find your pool volume. If you do not know it, work it out with the pool volume calculator first.
  2. Test the salt level with test strips or a meter. For a new pool or fresh water, enter 0.
  3. Enter the level your salt chlorinator wants. Many aim for about 3,200 ppm; your chlorinator's manual gives the exact range.
  4. Add the salt with the pump running, brush it around until it dissolves, and test again after about a day before adding more.

Salt per 10,000 gallons

Raise salt bySalt to add
500 ppmAbout 42 lb
1,000 ppmAbout 83 lb
2,000 ppmAbout 167 lb
3,200 ppm (new pool)About 267 lb

These are common starting points. Your site, climate and supplier may call for something different.

How the sum works

ppm means parts per million by weight. A US gallon of water weighs 8.34 lb, so the salt to add is gallons × 8.34 × the ppm you want to raise it by, divided by 1,000,000. Raising 15,000 gallons from 2,500 to 3,200 ppm takes 15,000 × 8.34 × 700 ÷ 1,000,000 = about 88 lb.

Which salt to use

Use salt sold for pools: at least 99% pure, with no iodine or anti-caking additives, which can stain. Add it a little short of the target, let it dissolve, then test, because readings vary and too much salt can only be fixed by draining water.

Common questions

How much salt do I need for a new pool?

About 267 lb per 10,000 gallons to reach 3,200 ppm from fresh water. A 20,000 gallon pool needs about 534 lb, or 14 bags of 40 lb.

What salt level should a saltwater pool have?

Most salt chlorinators want roughly 2,700 to 3,400 ppm, and many aim for about 3,200. Check your chlorinator's manual for its range.

How long does pool salt take to dissolve?

Usually several hours to a day with the pump running and some brushing. Test again after about 24 hours before adding more.

What if I added too much salt?

Salt does not evaporate, so the only fix is draining some water and refilling with fresh. To go from 4,000 to 3,200 ppm, replace about 20% of the water.

Can I use table salt or water softener salt?

Use pool salt. Table salt usually has iodine and anti-caking agents. Some plain water softener salt is pure enough, but pellets with additives are not, so check the bag.

Doing this job for a customer? Turn your numbers into a free written estimate on QuoteToPaid.

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