Swimming Pool Salt Calculator

Adding salt to your swimming pool is fairly straight-forward. However, calculating how much salt to add can complicate things. What you need is a swimming pool salt calculator.

Usually, there are two reasons why you would need to add salt to your pool. Either your salt chlorine generator alerted you that your pool was low in salt or you recently drained your pool, for whatever reason. Whether you’re adding salt to your swimming pool or diluting it, knowing how much salt to add back into the water is crucial to balancing your pool.

Let’s take a look at how pool owners can determine when their salt is low and how they can calculate how much salt to add. 

Swimming Pool Calculations

I hate to be the bearer of bad news, however, the next few steps require simple calculations. Don’t worry, though, if I can do it then I am confident that you can too.

How Much Salt Is Currently In Your Pool?

Before you can adjust the salt levels in your pool, you first have to determine how much salt is already there. INYO Pools offers various pool water testing equipment on our site that allows pool owners to test their salt levels. However, you can also take a sample of your water to test at most local pool stores.

Ideally, the recommended salt levels fall between 2700-3400 parts per million (ppm). However, each salt chlorine generator is different. Therefore, the minimum salt level needed for operation varies. We recommend referring to the owner’s manual for the exact number. Remember, make sure you use a reliable test kit to avoid inaccurate readings.

Once you have this number, write it down. We will use this number a little bit later. Next, you need to determine how many total gallons of water your pool has.

How Many Gallons Of Water Is In Your Pool?

In order to calculate how many gallons are in your pool, you need the length, width, and the average depth of your pool. Using the shape and size of your pool, you can calculate the total gallons.

The chart below shows how to calculate the number of gallons in a pool based on the shape. For non-standard shaped pools, it may be easier to break your pool into sections to calculate.



Example: If your rectangular swimming pool is 20 ft x 40 ft with an average depth of 3, the total number of gallons in your pool is 18,000 (20 x 40 x 3 x 7.5= 18000)


Using a Swimming Pool Salt Chart

Once you calculate how many gallons of water is in your pool and determine your current salt levels, you can finally figure how much salt to add.

Below is the swimming pool salt chart. On the left-hand side, are the current salt levels while the pool sizes are along the top. You can determine how much salt to add by taking your fingers, one for current salt level and one for pool size, and moving it across the table until they touch or intersect.

Example: Based on this salt chart, if your pool has 18,000 gallons and the current salt level is 1600 ppm, you need to add 240 ppm of salt to reach 3200 ppm.


Using A Saltwater Calculator

Salt charts are great tools for pool owners. In fact, most manufacturers provide salt charts for their salt chlorine generators inside the manual. However, if you misplaced your manual or simply don’t like using the salt chart, you can use a salt water calculator.

Most of the major manufacturers like Hayward and Pentair have swimming pool calculators. Much like a regular calculator, you still have to input the correct number of gallons in your pool and you still have to measure your current salt levels, as well.

It’s literally the same process. Below are examples of online calculators you can use to help streamline these calculations. Again, make sure you pay close attention to the parameters of the calculator. Some calculators determine how much salt you need to bring your pool to 3200 ppm while others will calculate to 3400 ppm.


Pentair Pool Water Salinity Calculator

The Pentair Salinity Calculator utilizes a sliding bar to select your current salt level and your pool volume. Pentair’s calculator determines how much salt you need to bring pools to 3400 ppm.




Hayward Water Chemistry Calculator

The Hayward Calculator is cool because not only can it calculate how much salt you need to add, it also has the capabilities to calculate your pH, total alkalinity, cyanuric acid, hardness, and phosphate levels. It’s a one-stop shop for calculations.

Other Resources

We have you covered if you’re looking for other blog posts, videos, or articles about managing the salt content in your pool. Check out our other resources for your salt pool.

How Often Should You Add Salt?

Water Chemistry For Salt Water Pools 

How To Maintain a Salt Water Pool

How To Reduce the Salt Level in Your Pool

6 thoughts on “Swimming Pool Salt Calculator

  1. I have read a lot of articles on this site on the pros & cons of salt chlorination vs traditional chlorination.
    I was wondering if it’s possible to have a both salt & traditional chlorination system for a swimming pool.
    And then based on necessity switch between the 2 systems if cost is not an issue.

    1. In theory, yes. But usually, you would switch to salt and only use shock to supplement the salt cell in cases of high demand. If you are going to take the money to switch to salt, it would seem a waste of money to keep adding chlorine tablets or liquid as well.

  2. I purchased a Summer Waves above ground po model number sfx1500. it said it has like a little over 5,000 gallons of water how many bags of salt do I add to it 4 saltwater pop

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