Pool Shock Calculator: How Much Shock Do You Need?

Wondering how much shock to add to your swimming pool? I walk through all of the calculations below and have a handy pool shock calculator you can use to determine just how much shock you should add. If you’re here for general pool maintenance, the calculation is pretty simple. If you have an algae problem in your pool, the amount of shock you need (and how many times you need to shock your pool) depends on the algae level severity. Let’s get into it.

Here are the steps you need to take:

Calculate Your Pool Volume

The amount of pool shock you need depends on the size of your pool in gallons. If you don’t know that number already, use my pool volume calculator below to figure out the approximate gallons of water in your pool.


Once you’re all set here, let’s move to the next step.

General Maintenance or Algae Problem?

The amount of shock you need depends on the current cleanliness of your pool.

Are you here for general maintenance and your pool is relatively clean? Great! You should shock your pool once every week or so and add about one pound of shock for every 10,000 gallons of pool water. The exact ratio will differ slightly depending on the type and brand of shock you use, so make sure to check the instructions on the bag too. The major types of shock are calcium hypochlorite (cal hypo), sodium dichlor (dichlor shock), and non-chlorine shock.

Are you here because of an algae problem? No worries! I can help you fix it. The amount of shock you need to add and how many times you need to shock your pool depends on the severity level of the algae infestation. In general, follow these guidelines based on the color of your pool water:

  • Teal green pool water: This is a smaller or newer algae bloom. You should double shock your pool and use two pounds of shock for every 10,000 gallons of pool water.
  • Dark green pool water: This algae has had time to grow significantly. You need to triple shock your pool and use three pounds of shock for every 10,000 gallons.
  • Black green pool water: This is a serious infestation and the hardest algae to kill. You need to quadruple shock your pool and use three pounds of shock for every 10,000 gallons.

Once again, the exact amount of shock you should add will differ slightly depending on the shock type and brand. Check the bag you’re using for more specific instructions.

Calculate the Amount of Shock You Need

Once you determine the volume of your pool and your situation, it’s time to calculate the amount of shock you need. Use my calculator below to get an estimate.


Alright, hopefully, you’re in a good spot now where you know roughly how much shock to add to your pool.

For more pool shocking tips, check out my guides and research below.

Have questions? Drop me a line; always happy to help.

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