Pool Salt Calculator
Most saltwater pools run best between 2,700 and 3,400 ppm of salt, with 3,200 ppm the ideal level for most chlorine generators. Enter your pool volume and current salt reading to get the exact amount of salt to add in pounds, 40-lb bags, and kilograms. Everything runs in your browser — nothing is uploaded and no signup is needed.
How Much Salt to Add by Pool Size
Pounds of salt needed to raise your salt level, with 40-lb bags (rounded up) in parentheses. All values come from the same formula the calculator uses.
| Pool volume | +500 ppm | +1,000 ppm | +2,000 ppm | Full fill (0 to 3,200 ppm) |
|---|---|---|---|---|
| 5,000 gal | 21 lb (1) | 42 lb (2) | 84 lb (3) | 134 lb (4) |
| 10,000 gal | 42 lb (2) | 84 lb (3) | 167 lb (5) | 267 lb (7) |
| 15,000 gal | 63 lb (2) | 126 lb (4) | 251 lb (7) | 401 lb (11) |
| 20,000 gal | 84 lb (3) | 167 lb (5) | 334 lb (9) | 534 lb (14) |
| 25,000 gal | 105 lb (3) | 209 lb (6) | 417 lb (11) | 668 lb (17) |
| 30,000 gal | 126 lb (4) | 251 lb (7) | 501 lb (13) | 801 lb (21) |
Round up to the nearest bag — a slightly higher level within the acceptable range is better than running low.
Which Salt to Use
Use pool-grade salt that is at least 99.8% pure sodium chloride (NaCl). Additives that are harmless in other salts stain pool surfaces and shorten the life of your salt cell.
| Product | Use it? | Why |
|---|---|---|
| Pool salt (99.8%+ pure NaCl) | Yes | Fast-dissolving and additive-free |
| Water-softener pellets | No | Anti-caking agents can foul the salt cell |
| Rock salt | No | Mineral impurities can stain surfaces |
| Table / iodized salt | No | Iodine and anti-caking additives |
Check Your Salt System's Target
The right target level is set by your salt chlorine generator, not by a universal number. Commonly published manufacturer targets cluster between 2,700 and 3,500 ppm — Hayward AquaRite, Pentair IntelliChlor, Jandy AquaPure, and CircuPool systems each specify their own range and low-salt cutoff.
Always confirm the exact target in your system's manual, then enter it as a custom target above. Running below the cutoff stops chlorine production; running well above it accelerates corrosion on heaters, rails, and fittings.
Why Your Salt Reading Changes
Salt is not used up by the chlorine generator — it only leaves the pool when water leaves the pool. Retest after:
- Heavy rain — overflow carries salty water out and dilutes what remains
- Splash-out — every gallon over the edge takes its salt with it
- Backwashing the filter — salt-laden water out, fresh water in
- Leaks or draining — any water loss removes salt
Evaporation works the other way: the water leaves but the salt stays, so readings slowly climb in hot, dry weather.
Common Questions
How many gallons is my pool?
To calculate your pool's volume: For rectangular pools, multiply length x width x average depth x 7.5. For circular pools, use (diameter)² x average depth x 5.9. For oval pools, multiply length x width x average depth x 6.7. Always measure in feet for accurate results.
How do I add salt to my pool?
Distribute salt evenly around the pool's perimeter. Brush to help dissolve and prevent staining. Run the pump for 24 hours to circulate. Don't add through skimmers. For best results, add salt when the water is warm and there's no rain forecast.
How long after adding salt to a pool can you swim?
It's generally safe to swim once the salt has fully dissolved, which typically takes 24 hours. Always test the water chemistry before swimming to ensure proper balance. If the salt hasn't fully dissolved, it might irritate your skin and eyes.
How do you lower the salt level in a pool?
The most effective way to lower salt levels is to partially drain the pool and refill with fresh water. You can also use a reverse osmosis system. Natural dilution from rain can help over time. Regular backwashing slightly reduces salt levels too. To size the drain: the fraction to replace equals 1 - (target ÷ current). For example, at 4,000 ppm targeting 3,200 ppm, drain and refill about 20% of the water.
What are signs of too much salt in a pool?
Symptoms include salty-tasting water, eye and skin irritation, corrosion of metal pool equipment, and malfunctioning salt chlorine generator. You might also notice salt residue on pool surfaces or equipment. Always test salt levels regularly to avoid these issues.
What are signs of too little salt in a pool?
Low salt levels primarily affect salt chlorine generators, causing reduced chlorine production. This can lead to algae growth, cloudy water, and potential health risks from inadequate sanitization. The pool might also have a strong chlorine smell, ironically indicating not enough chlorine.
How do you test the salt level of a pool?
Use salt test strips or a digital salt meter for quick readings. For more accurate results, use a liquid titration test kit. Many modern salt chlorine generators have built-in salt level sensors. Always follow the manufacturer's instructions for the most accurate results.
What does pool salt do?
Pool salt is used in saltwater chlorination systems. The salt chlorinator uses electrolysis to convert dissolved salt (NaCl) into hypochlorous acid (HOCl), which sanitizes the pool. This provides a constant, lower level of chlorine, reducing eye and skin irritation compared to traditional chlorine pools.
How do you calculate how much salt you need for your pool?
The calculator uses the formula: Salt Needed = ((Ideal PPM - Current PPM) x Pool Volume x 8.34) / 1,000,000. PPM stands for parts per million, a measure of concentration. Salinity refers to the salt content in water. The factor 8.34 is the weight of a gallon of water in pounds, used to convert volume to weight.
What's the ideal salinity range for a saltwater pool?
The ideal salinity range for most saltwater pools is between 2700-3400 ppm (parts per million), with 3200 ppm being optimal for most salt chlorine generators. This range ensures efficient chlorine production while maintaining comfortable swimming conditions and protecting pool equipment from corrosion.
How many bags of salt do I need for my pool?
Pool salt is sold in 40-pound bags, so divide the pounds needed by 40 and round up. Starting from fresh water (0 ppm) and targeting 3,200 ppm, a 10,000-gallon pool needs about 267 pounds (7 bags), a 15,000-gallon pool about 401 pounds (11 bags), and a 20,000-gallon pool about 534 pounds (14 bags).
What kind of salt can I use in a pool?
Only pool-grade salt that is at least 99.8% pure sodium chloride (NaCl) — evaporated, granulated, non-iodized, and free of anti-caking agents. Never use water-softener pellets, rock salt, or iodized table salt: their additives and impurities can stain pool surfaces and damage the salt cell.