Pool Salt Calculator

Enter your pool size and current salt level to get an exact dosage in pounds and bags. Includes a drain and refill calculation if your salt is too high, plus a generator output recommendation based on your conditions.

Pool Parameters

Shape & Salt Levels

Pool Shape & Size

Salt Levels

Low
< 2,700 ppm
Ideal
2,700-3,400
High
> 3,400 ppm

Generator Conditions

Results

Salt Action Plan

Pool volume: 19,149 gal / 72,478 L
Effective Salt Level
2,800ppm
400 ppm below target
Salt to Add
Weight
64.5 lb
29.3 kg
Bags needed
2
x 40 lb bags  /  2 x 25 kg

Add salt by broadcasting it around the pool perimeter with the pump running. Allow 24 hours to fully dissolve before retesting. Never add more than 10 lbs per 1,000 gallons in a single dose.

Recommended Generator Output
65%

Peak summer UV and heat accelerate chlorine loss.

What is a pool salt calculator?

A pool salt calculator tells you exactly how many pounds of salt to add to reach your salt water chlorine generator's (SWG) target level, accounts for fresh water top-ups that dilute your existing salt, and tells you how much to drain and refill if your salt is too high. It also recommends a generator output percentage based on your pool size, bather load, and season.

Unlike a basic dosing guide, this tool factors in water dilution from top-ups - a commonly missed variable that causes pool owners to under-dose after refilling from evaporation or backwash loss.

Why accurate salt dosing matters

Protects your SWG cell

Running a salt cell below its minimum salt level (typically 2,400-2,700 ppm) causes the cell to work harder and shortens its lifespan. Most generators auto-shutoff to protect the cell, leaving your pool unsanitised.

Prevents corrosion from excess salt

Salt above 4,000-4,500 ppm accelerates corrosion on pool ladders, handrails, heater components, and the cell itself. The only remedy is draining and diluting - an expensive fix.

Optimises generator efficiency

Salt within the ideal range (2,700-3,400 ppm) lets your generator produce chlorine at peak efficiency. Low salt means more generator run time for the same FC output, increasing electricity costs.

Frequently asked questions

What type of salt should I use?
Use plain NaCl (sodium chloride) with at least 99% purity - food-grade, water softener, or pool-grade salt all work. Avoid salt with anti-caking agents, iodine, or other additives as these can stain pool surfaces and damage the cell.
How do I test my pool's salt level accurately?
A digital salt meter (titration-based) is the most accurate method. Salt test strips are convenient but less precise - they can read 200-400 ppm off. Your SWG display shows an estimated reading but it drifts over time and should be calibrated against a meter periodically.
Why does my salt level keep dropping?
Salt does not evaporate or get consumed by the chlorine generation process - it is recycled. Salt levels drop only when water leaves the pool: backwashing, splash-out, overflow from rain, or leaks. Every time you top up with fresh water you dilute the salt concentration, which is why this calculator includes a water added field.
Can I add too much salt at once?
Yes. Adding more than 10 lbs per 1,000 gallons in a single dose can create a temporarily high-concentration area near the inlet that stresses pool surfaces and equipment. Split large doses over 24-48 hours and run the pump continuously to distribute it.
What generator output percentage should I run?
There is no single correct answer - it depends on pool volume, bather load, season, and your current FC level. The calculator gives a starting recommendation based on these factors. The real-world check is your FC test result: if FC is consistently low, raise the output or run time; if it is consistently high, reduce it.
How long after adding salt can I swim?
Wait at least 30 minutes after adding salt with the pump running, and ideally retest before swimming to confirm the level has evened out. Full dissolution and distribution can take up to 24 hours for large doses.