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.

INYO’s Calculator 

If you are in need of calculations including how many gallons of water your pool holds, how long you need to run your pump, and other chemical calculations, INYO has a one-stop calculator. 

26 responses to “Swimming Pool Salt Calculator”

  1. VOS Avatar

    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. Matthew Simmons Avatar

      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.

      1. Ines Avatar

        purchased a small above swimming pool (10×30”) I put 1oz Clorox(shock extra blue) the chlorine is perfect but the ph is low, I am not an expert in pools since my husband was the one in charge of everything but since he passed the way, nothing is the same, my granddaughter is staying with me in the weekends so I had to got at list a small swimming pool but do not really know how to keep clean. Can you give an idea in how to to keep clean? This pool is only 1475 gallons.
        I would prefer to do not use chlorine just salt but I don’t know how much

  2.  Avatar

    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

    1. Kyle Avatar

      Use the 10000 gallon numbers and cut them in half.

    2. Phyllis Avatar

      I have a 30×54 round pool how many 40 lb bags of salt should I add?

      1. Matthew Simmons Avatar

        Using the formula explained in the article, your pool appears to be around 21,000 gallons. If the starting salinity level is 0, you would need to add about 500 – 550 pounds of salt.

  3. Lauren Avatar

    How much salt is 105 ppm? I mean in weight?

    1. Matthew Simmons Avatar

      As you can tell by the chart and the article, that all depends on the body of water.

  4. Michelle Weston Avatar

    First time Salt water change over with a sand filter pump 8600 gals/18″ x 48″/Round, Coleman Swim Vista Series II pool just thinking better all the way around to change chlorine to salt. Filters to Sand instead but I’d be starting from new I have zero idea how much salt but I’m researching with help from your Salt Calculator this type salt and sand is new pool chemistry for a 20yr above ground normal chlorinated po person Don’t know if it’s easier or complicated
    Terrified as 1st Timer…Newbie on Sand & Dalt

    1. jen Avatar

      I changed to a salt water pool 2 years ago, after years of having a chlorinated pool. That I would not go back to.
      My salt water pool has it beat all the away around. Way less chemicals to mess with. Hardly any of the problems with keeping it ready to swim. The burning eyes, and green hair and bathing suits with elastic in them don`t wear out as fast are GONE. Now its softer skin.
      Good luck,
      Never going back!

  5. Laurie Avatar

    Getting a 15 ft round pool by 48 inches. Probably fill to 44 inches. Having a hard time figuring out salt requirements as your calculator and tables start with much bigger pools, more gallons of water. Any help? Also any recommendations on converters would be appreciated. Plan on keeping pool up for the season only. First time real pool buyers. Excited and nervous.

    Thanks.

    1. Christy Avatar

      Mine is a 16’x42″ and I normally put 1 bag in it and check in a day or so to see what my intex salt water pump says. If it says salt low, I’ll add another and that’s normally all I need for the summer. My husband told me calculations showed 4 bags last year and that was way too much. I had to drain it 3/4 and refill with water.

    2. Ines Avatar

      I purchased a small above swimming pool (10×30”) I put 1oz Clorox(shock extra blue) the chlorine is perfect but the ph is low, I am not an expert in pools since my husband was the one in charge of everything but since he passed the way, nothing is the same, my granddaughter is staying with me in the weekends so I had to got at list a small swimming pool but do not really know how to keep clean. Can you give an idea in how to to keep clean? This pool is only 1475 gallons.
      I would prefer to do not use chlorine just salt but I don’t know how much

  6. Khay Gardner Avatar

    How much salt do we add to 18 x 33 x 52 after installing for the first time?

    1. Matthew Simmons Avatar

      Using a pool volume calculator, you can estimate your pool has about 14k gallons. Refer to the chart to see how much salt is required according to your starting ppm.

      1.  Avatar

        😲p

  7. JR Padilla Avatar

    I have a 20×48 Inter radious Pool how many bags of salt do I need to use?
    How can I find out how many gallons of water is this pool?

    1. Matthew Simmons Avatar

      In the article, there is a formula for calculating your pool’s gallons or if you google “pool volume calculator” a whole litany of options comes up.

  8. shelly Avatar

    I have a 5000 gallon pool, and the salt strip reads 370, how much salt do I need?

    1. Matthew Simmons Avatar

      Using your 5,000 gallons, we can use the chart to calculate the salt you need. The salt chart only goes down to 8,000 gallons, finding what percentage of 8,000 gallons your pool makes u is pretty easy. For example, if you have 5,000 gallons, that is 63 percent of 8,000. So, find your current salinity level on the chart, then slide over to the value under the 8,000-gallon column. In this example, our ppm is 0, so 63 percent of 213 pounds of salt is 134 pounds.

    2. CC Avatar

      ~Three 40lb bags

  9. Martina Avatar

    I have a round pool above ground 16ft by 3 1\2 depth how many gallons is that and how much salt do I need I already put in three bags but it shows low salt

    1. Matthew Simmons Avatar

      Using a pool volume calculator, your pool gallonage is 5300-6100 gallons depending on the true wall height of your pool. Using that sum, you can reference the pool chart. The salt chart only goes down to 8,000 gallons, but you can reckon that by finding what percentage of 8,000 gallons your pool makes up. For example, if you have 5,000 gallons, that is 63 percent of 8,000. So, find your current salinity level on the chart, then slide over to the value under the 8,000-gallon column. In this example, our ppm is 0, so 63 percent of 213 pounds of salt is 134 pounds.

  10. Nicole Avatar

    I don’t have a way to measure pounds of salt. Can I measure in cups or liters?? All I can find a conversion for is table salt but I don’t know if that is the same thing.

  11. Rohan S.F. Duykers Avatar

    You use (average safe margin) 2 pound of salt per 100 gallons of water. So work out your volume in inches, convert inches to gallons (100ci=0.4329gl) then just multiply. Eg; round pool/spar = radius 29inch depth 20 = ^vol 52,842ci. So round off to nearest cubic inch. In this case I would round up to 53,000ci. Cubic inches to gallons = 100ci=0.4329gl, so basically halve it to simplify the math. So in this case it would be 229.43723gls. So round that to 230gls. Now simply double it and divide by 100 = 4.6pounds of salt needed for base line fresh fill. I hope this helps you all 😉 happy swimming

Leave a Reply

Your email address will not be published. Required fields are marked *