Pool Salt Calculator
Calculate how much salt to add to your pool based on pool volume, current salinity, and target salinity level.
Project Details
Don't know your pool volume? Length × Width × Avg Depth × 7.5
Test with salt strips or digital meter. New fresh water is ~500 ppm
Most salt chlorine generators require 2,700–3,400 ppm. Check your model's manual
Estimated Cost
Low
$30
Average
$42
High
$60
Cost Breakdown
Materials
| Item | Qty | Low | Mid | High |
|---|---|---|---|---|
| Pool Salt (40-lb bags) | 6 bags | $30 | $42 | $60 |
| Subtotal | $30 | $42 | $60 |
Labor & Fees
| Item | Qty | Low | Mid | High |
|---|---|---|---|---|
| Subtotal | $0 | $0 | $0 |
Notes
- • Need to raise salt level by 1,700 ppm (from 1,500 to 3,200 ppm).
- • Total salt needed: 213 lbs (6 × 40-lb bags).
- • Add salt gradually — no more than 200 lbs at a time. Run the pump for 24 hours, then retest before adding more.
- • Pour salt into the deep end while walking around the pool's perimeter for even distribution.
About the Pool Salt Calculator
A saltwater pool uses a salt chlorine generator (SWG) to convert dissolved salt into chlorine, eliminating the need to handle liquid or tablet chlorine. Maintaining the correct salt level is essential for your generator to work efficiently. Our calculator tells you exactly how many pounds (and bags) of salt to add based on your pool volume, current salt reading, and target level.
How We Calculate Pool Salt
We use the standard pool industry formula: pounds of salt = pool volume (gallons) × desired ppm increase ÷ 120,000. This accounts for the fact that 1 pound of salt raises approximately 1 ppm in 120 gallons of water. We then adjust for salt purity (pool salt 99.8%, solar salt 99.6%, rock salt ~96%) and round up to the nearest 40-lb bag.
Factors That Affect Pool Salt
Factors that affect how much salt you need: pool volume (larger pools need proportionally more), current salt level (test before adding), target level (varies by generator model), salt purity (lower purity = slightly more needed), and recent water changes (rain, backwash, or refill dilutes existing salt).
Planning a larger project? You may also want to estimate costs for water damage repair cost, bathroom remodel cost, or pine straw.
Sources
- • Pentair — SWG Salt Level Guidelines (2025)
- • National Plasterers Council — Saltwater Pool Maintenance
- • Pool industry standard: 1 lb salt per 120 gallons raises ~1 ppm
Pricing data as of 2026. Costs vary by location and market conditions.