01
The purpose
What does this calculator estimate?
How many bags of salt to reach your generator's target ppm — or how much to drain if you're over.
Water Chemistry · B8
Pool Salt Calculator
How many bags of salt to reach your generator's target ppm — or how much to drain if you're over.
Measure the inputsCheck your generator's manual — target salt varies by brand, commonly 2,700–3,400 ppm.
Read the full resultAdd salt to the shallow end and brush it around; run the pump 24 hours before testing.
Check the boundaryDon't run the salt cell until the salt has fully dissolved or you'll get a false low reading.
Useful forWater ChemistryPlanningComparisonVerification
Live calculation
Salt adjustment
✓ Checked May 2026
Enter current and target salt for your generator.
Recommended dose
—
Enter the required values to calculate.
Enter the known values. Let the engine handle the calculation.
✓ Formula checked↻ Live result○ No account needed
Planning estimate only. Confirm product labels, equipment specifications, qualified-professional advice and local requirements before acting.
The result, explained
Use the Pool Salt Calculator result with context.
How many bags of salt to reach your generator's target ppm — or how much to drain if you're over.
02
The tool
What information does it use?
- Pool volume: enter a measured or verified value
- Current salt level: From a test strip or your SWG display, in ppm.
- Target salt level: Check your generator — usually 2,700–3,400 ppm.
- Salt type: Use pool-grade or food-grade salt, 99%+ pure.
03
The method
How to use this calculator
- Pool volumeEnter the value you can verify.
- Current salt levelFrom a test strip or your SWG display, in ppm.
- Target salt levelCheck your generator — usually 2,700–3,400 ppm.
- Salt typeUse pool-grade or food-grade salt, 99%+ pure.
04
The relationship
The formula in plain English
Salt (lbs) = (Target − Current) ppm × Volume gal × 8.34 ÷ 1,000,000
Divide by salt purity (≈0.99). One 40 lb bag raises ~15,000 gal by about 320 ppm.05
Worked through
A worked example: 15,000 gal pool, salt 2,000 → 3,200 ppm
- Increase = 3,200 − 2,000 = 1,200 ppm
- lbs = 1,200 × 15,000 × 8.34 ÷ 1,000,000 = 150 lb
- ÷ 0.99 purity ≈ 152 lb → 4 bags
| Current salt | Salt to add | 40 lb bags | Approx. cost* |
|---|---|---|---|
| 0 ppm | 405 lb | 11 | ~$110 |
| 1,000 ppm | 278 lb | 7 | ~$70 |
| 2,000 ppm | 152 lb | 4 | ~$40 |
| 2,500 ppm | 88 lb | 3 | ~$30 |
| 3,000 ppm | 25 lb | 1 | ~$10 |
| 3,200 ppm | 0 lb | 0 | at target |
06
Why it matters
How the result supports the next decision
Check your generator's manual — target salt varies by brand, commonly 2,700–3,400 ppm.
Add salt to the shallow end and brush it around; run the pump 24 hours before testing.
07
Good inputs
Improve the estimate before relying on it
- Check your generator's manual — target salt varies by brand, commonly 2,700–3,400 ppm.
- Add salt to the shallow end and brush it around; run the pump 24 hours before testing.
- Don't run the salt cell until the salt has fully dissolved or you'll get a false low reading.
- Salt only leaves the water through splash-out, backwashing, and draining — never evaporation.
- If you overshoot, the only fix is to drain some water and refill; you can't remove salt chemically.
08
The boundary
How to interpret the result
Follow the product label, add chemicals separately and retest before another dose.
The engine reports invalid inputs and safety warnings beside the result. Resolve those messages before using the estimate.
09
Before acting
What should override this estimate?
- Measured site conditions and current test results
- Product labels and manufacturer specifications
- Qualified-professional advice and applicable local codes
10
Common questions
Frequently asked questions
How much salt does a saltwater pool need?
Most saltwater chlorine generators run best between 2,700 and 3,400 ppm, but the exact target depends on the brand — always check your cell's manual. Too little salt and the cell won't produce chlorine; too much can trigger an error and accelerate corrosion.
How many bags of salt do I need?
It depends on your volume and how far below target you are. As a rule of thumb, one 40 lb bag raises about 15,000 gallons by roughly 320 ppm. The calculator gives an exact bag count for your pool and the gap you need to close.
How do I lower salt that's too high?
There's no chemical that removes salt — you drain part of the pool and refill with fresh water. The calculator shows what percentage to replace. High salt rarely happens unless someone over-added; normal operation slowly loses salt over time.
Why does my salt level drop over time?
Salt leaves the water through splash-out, backwashing the filter, draining for winter, and rain overflow — but never through evaporation, which leaves salt behind. Expect to top up salt a couple of times a season, more if the pool sees heavy splashing.
What kind of salt should I use?
Use pool-grade or food-grade salt that's at least 99% pure sodium chloride, with no additives, anti-caking agents, or iodine. Solar salt and water-softener salt work if they're pure. Avoid rock salt, which contains impurities that can stain.
How much salt for a 15,000 gallon pool?
To go from 2,000 to 3,200 ppm in 15,000 gallons takes about 152 lbs of salt — roughly four 40 lb bags.
Can I add salt and run the generator right away?
No — wait until the salt fully dissolves (about 24 hours with the pump running) before turning the cell on, or you'll get a false reading.
Does a saltwater pool taste salty?
Barely. At 3,200 ppm the salt is about a tenth of seawater — most swimmers notice only a faint softness, not a salty taste.
Primary sources
Use the result with current guidance.
These official references support safe planning context. Product labels, local requirements and qualified-professional advice take priority over a general calculator estimate.