How To Calculate the Cost of Running A Pool Pump

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One of the most powerful consumers of energy in homes with swimming pools are pool pumps. With the rising electric costs, it is important to understand how much it costs to run a pool pump. The following guide will explain how to easily calculate the cost of running a pool pump.

Step by Step

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Step 1

Locate the voltage and amperage rating of the pump. The specifications should be listed on the motor label. In our example we used a 1.5HP Hayward Super Pump. The voltage rating is 115/230 and the amp rating is 18.6/9.3. If you run a pump on the lower voltage rating (115) you will select the higher amperage rating (18.6). If you run the pump on the higher voltage (230) you will select the lower amperage rating (9.3). For this example we will use the 230 voltage and 9.3 amperage rating.

Step 2

Multiply the voltage rating by the amperage rating. This will give the total watts. Example: 230 volt X 9.3 amps = 2,139 watts

Step 3

Divide the total watts by 1,000 to get kilowatts (kW). Example: 2,139 watts / 1,000 = 2.139 kW

Step 4

Multiply the hours per day you run the pool pump by the kW. This total will be the kWh per day. Example: 8 hours/day X 2.139 kW = 17.112 kWh per day.

Step 5

Multiply the kWh per day by the cost per kWh. The cost per kWh can be found on your most recent power bill. The result will tell you how much it costs to run your pump each day. Example: 17.112 kWh a day x .12 cents per kWh = $2.05 per day to operate the pool pump

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(1 to 13 of 13)

 Posted: 2/4/2019 

FYI, if you already have a pool and pump in service, the most accurate way to calculate costs is to just directly measure the power using your electric meter. My meter shows instantaneous total wattage for the house on the LCD display, so to measure a pump power consumption, I just made sure everything in the house is at a constant load (no need to turn things off unless they are intermittent, like a microwave on less than full power, or a washing machine, etc.) To keep it simple you could go ahead and shut off anything you're not sure if it is constant or not. Then watch your meter with pumps off for a while until you establish a consistent average baseline wattage (for example, mine was about .4 kW). Then go ahead and turn on a pump and do the same thing to establish the new average with it on. Then subtract the two values. To make sure things like a refrigerator didn't happen to cycle on at just the wrong time, you can repeat the process until you are satisfied that your results are consistent. I did this with an Intelliflo variable speed pump and measured anywhere from about 200W at very low speeds to 2500 Watts at full speed. I don't know what the RPM's were as my model doesn't show that. It just has arrows allowing you to adjust it up or down. I found that at about 400W, the speed was enough to keep the pool cleaner rolling around and working properly, as well as the chlorinator. The power consumption generally increases much more quickly than flow rate, so best efficiency is at low flow rates and longer run times as long as not too low for equipment to work, like heater, chlorinator, pool cleaner, etc.) You can do the same method for any other accessories, but it's a bit limited by the resolution of the meter and any fluctuations from refrigerators when measuring very small loads. My meter only shows to the nearest .01 kW (10 watts). My spa light is 50 watts, for example and my pool light is 100 watts. My waterfall uses 2000 watts!
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 Posted: 11/12/2017 

Bob - It costs considerably more to run your pump at high speed than low speed. It uses more amps.
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 Posted: 12/6/2018 

I believe you may have that backwards, a pump running at full will run more efficiently than one that is throttled down
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InyoPools Product Specialist  Posted: 12/7/2018 

Hello Dave - A pump running on a lower speed is more energy efficient. For example, a 1HP 230v 2-speed motor will draw 7.0 amps on high speed (3450) and 2.3 amps on low speed (1725 rpm). Let's say it takes 8 hours to turn the water over once on the high speed and 16 hours to turn the water over once on low speed. The KWh per day of the high speed would be 11.27. The KWh per day of the low speed is 8.464. I know these numbers can change slightly due to power fluctuation but the lower speed is 28% more efficient in that example. The energy efficiency is even greater when you compare variable speed pumps to single speed pumps.
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 Posted: 11/7/2017 

Does it cost more to run the pump at high speed or low speed?
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 Posted: 11/1/2017 

Hi, just wondering if you followed up on the comment regarding hp, and which calculation is correct? Thanks
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InyoPools Product Specialist  Posted: 7/31/2017 

Anonymous (power calc) - Thank you for your feedback. I will look into this.
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Anonymous  Posted: 7/30/2017 

There is a problem with this calculation. The amps drawn include reactive power. There are two components to power active power measured in watts and reactive power measured in volt amps. Consumers are only billed for active power, watts. Unslee you know the power angle you can't calculate the amount of active power from the information given. However, if you know the hp rating of the motor you can simply multiply that by 746, which will convert hp to watts. Then dived by 1000 to get kW and then figure out cost as per the instructions.
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InyoPools Product Specialist  Posted: 6/20/2017 

Anonymous (pool cost) - I don't know your numbers, but unless you have a much bigger pump, it sounds like you may be off by a factor of ten. Did you multiply the KWh per day by the cost of a KWh is step 5?
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Anonymous  Posted: 6/20/2017 

If I'm doing this correctly it tells me it's $20 a day to run my pool for 8 hours!!! That means my electric bill would be $699 a month just for the pool. Is that accurate ?
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InyoPools Product Specialist  Posted: 9/10/2015 

NeilBJ- Thank you for your comment. You are correct. To get our units in order, I changed Step #3 to read, "Divide the total watts by 1,000 to get kilowatts (kW). Example: 2,139 watts / 1,000 = 2.139 kW; and Step #4 now reads, "Multiply the hours per day you run the pool pump by the kW. This total will be the kWh per day. Example: 8 hours/day X 2.139 kW = 17.112 kWh per day.
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 Posted: 9/8/2015 

Re: Step 3
Step 3
Divide the total watts by 1,000. The result of this will provide a kilowatt hour rating (kWh). Example: 2,139 watts / 1,000 = 2.139 kWh.

This calculation merely converts watts to kilowatts. The answer should be 2.139 kilowatts.

Step 4 is the calculation for kilowatt hours:

8 hours X 2.139 kilowatts = 17.112 kilowatt-hours

Your calculation results in 12.112 kilowatt–hours exp 2
One thing I learned in college is to make sure the units are consistent

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 Posted: 1/29/2015 

Brilliant !!!
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