Pool salt calculator
Enter your pool volume, your current salt reading and your target, and this calculator tells you how many pounds of salt to add — using the standard conversion rather than a guess.
Enter your current salt reading to see how much salt to add. Take it from a salt test strip, meter, or your chlorinator — guessing a starting level is how pools get overdosed.
How the calculation works
pounds of salt = (target ppm − current ppm) × gallons ÷ 120,000
The divisor comes from the industry convention that 1 lb of salt per 1,000 gallons raises salinity by about 120 ppm. We show it rather than hide it, and you can read its source and review status.
Typical salt targets
Most salt chlorinators run best between 2700–3400 ppm, and 3,200 ppm is a common target. Your equipment manual is the authority for your specific cell — check it before adjusting.
Adding salt safely
- Test first. A salt test strip or meter, or your chlorinator's own reading, gives you the current ppm.
- Run the pump so there is good circulation before you add anything.
- Add about 80% of the calculated amount, then wait 24 h with the pump running.
- Retest and add the remainder if you are still below target.
- Brush the pool until the salt has dissolved — undissolved salt can stain or damage surfaces.
- Never pour salt into the skimmer.
Don't know your volume? Start with the pool volume calculator — every salt calculation depends on it. We pass the result through automatically when you use the "use this volume" link.
Related
- Pool volume calculator — gallons and litres for any shape
- Methodology — ppm-lb-per-gallon and salt-target-range
- How to backwash a pool filter — every backwash sends water (and salt) to waste, so salinity drifts down over a season
- Pool maintenance schedule — when to test salt, and everything else