Pool Salt Calculator

Estimate salt to bring a pool to the target ppm.

How the Math Works

The Pool Salt Calculator uses a precise formula to determine the amount of salt needed to adjust your saltwater pool's salinity. The equation is salt (lb) = gallons × 8.345 × (target − current) ÷ 1,000,000. Here, 8.345 represents the weight of one gallon of water in pounds, ensuring the calculation accounts for the pool's total water volume. The (target − current) term measures the difference between your desired salinity level (in parts per million, or ppm) and your pool's current salinity. Dividing by 1,000,000 converts the ppm difference into a fraction, allowing the formula to scale the salt requirement accurately for pools of any size.

Practical Applications

To use this calculator, first measure your pool's current salinity with a salt test kit and determine your target salinity (typically between 2,700–3,400 ppm for most saltwater systems). Input the pool's volume in gallons, current salinity, and desired salinity into the calculator. The result tells you exactly how many pounds of salt to add. For best results, spread the salt evenly across the pool surface while running the filtration system to ensure thorough mixing. Always add salt gradually and retest salinity after a few hours to avoid over-correction.

Day-to-Day Use

This calculator simplifies saltwater pool maintenance by eliminating guesswork and ensuring optimal efficiency. By precisely calculating salt additions, you prevent over-salination, which can damage equipment or irritate swimmers, and avoid under-salination, which reduces chlorine production. Regular use helps maintain consistent water quality, extends the lifespan of your salt cell, and ensures your pool remains a safe, inviting oasis. Plus, accurate dosing saves money by preventing unnecessary salt purchases while keeping your pool's automated system running smoothly.

Worked example

15,000 gal, 3,200 target, 500 current → ~338 lb.

FAQ