Shower Water and Energy Use Calculator

( Updated 1/20/09 ) After making the various calculations for the Shower Saving Tips article, I realized that it would be helpful to have a water calculator that would not only calculate the amount of water used, but also energy. This calculator takes in various sets of inputs including:

Water Parameters

  • Average Shower Time: Enter the amount of time you normally shower.
  • Shower Head Water Usage: The number of gallons per minute your shower head uses. If you cannot find this value, many shower heads made today use 2.5 gallons per minute.
  • Cost: The cost of water per 1000 gallons used. The national average is $2 per 1000 gallons.

Water Heater Parameters

  • Energy Type: The type of energy you water heater uses. The typical water heater uses either gas or electric.
  • Cost: The cost of one unit of the particular energy type your water heater uses. You can select the state you live in to get the average energy cost for the particular energy type your water heater uses.
  • Efficiency: Is measured as an Energy Factor (EF), which is usually listed beside the EnergyGuide label. The higher the number, the more energy efficient the water heater. On average, an electric heater has an efficiency rating of .92 while a natural gas heater has a rating of .59.
  • Water Temperature: The temperature of the ground water before being heated.
  • Shower Temperature: The temperature at which the shower water is raised to. A temperature about 125 – 130 °F can be dangerous for use.

Hopefully this calculator helps you determine how much a shower really costs you and the amount you can save by reducing your shower time. Please share your findings with this calculator.

Water Use
gallons / minute
/ 1000 gallons

Water Heater Usage

If you enjoyed this post, keep yourself updated with all my latest posts:
Subscribe to my RSS Feed

RSS Icon
Sign Up for Daily Morning Emails


  1. Wow. Thanks so much for this. I had no idea how much water I used. Because I rent (and dont pay for water) I never really paid attention to it, but I use so much water to basically wake me up.

  2. I use a lot of hot water in the evening. It helps me relax and puts me to sleep. I always wondered how much $ do I spend, because I really love long showers.

    • kins
    • January 13th, 2009

    There are many more factors in determining the actual cost, such as the shower water temp, the cold water temp the water has to be raised from (much different from alaska to florida), and your water heater efficiency rating.

    • Pays to Live Green
    • January 13th, 2009

    kins: Thanks for pointing these out as I forgot to include them in my post. This is just a first draft of this calculator. I am going to add a field for the cost of water and some of the other factors as mentioned. I currently used many default values for efficiency, water temperature rise and water cost that I will be sure to add to my post above. I am collecting more data on each state to make it more automated for the user on some of these values. I will also be adding some additional features like the ability to choose the time periods over which the calculations are made, but that is a little further down the road.

  3. Great idea dear.Thanks a lot.So hereafter no need to worry about water bills.

  4. Hi Patrick,

    Confirmed … as I commented on your other post … according to your calculator, my wife’s 30 minute showers cost us almost $3 a day … yikes.


    • Dananjaya
    • March 9th, 2009

    I would thank you for Energy cal support. does this work with 230V/50Hz supply?
    as i live in Sri lanka.
    if you can supply a load cal system for above to use with 12V DC to 230V / 50Hz AC systems I am willing to buy it. I work with solar to AC power.


    • Greg B
    • January 29th, 2010

    Hey, thanks for the info…I live with my brother and his son (2 1/2 men?)….my nephew takes 25 min showers (not sure what he;s doing in there for that long)….but we pay 5.8 cents per Kwh….so it’s not so bad…I thought that I was paying a lot more for his showers…turns out to be only 40 cents per shower….

  5. Another great tool,After knowing how much water i waste using showers i think ill prefer bucket bath rather than a shower.Im really sorry after realising the wastage of water i did.

    • cass
    • July 8th, 2010

    I’m confused…is this based on one shower per day?

    • Cass,

      I believe the calculator is a per shower basis, so if you shower 2 times a day at 15 minutes each, just multiply your result times 2.


    • Cass B
    • November 30th, 2010

    What are the units of your energy in the table

  6. This is fantastic. One thing is that I think your assumption of $2/1000 gallons is really low. I know including water AND sewer (which is a valid cost) we pay .01/gallon in the City of Asheville, NC. That’s $10 for 1000 gallons.

    Just some input. I do think it’s important to make it really clear that this is only per shower per day. The real numbers for the average family are 4-5 times that.

    • Helen
    • September 12th, 2011

    Hi there, this has really helped me with my economics class and I was wondering if it was possible to add the option of solar power and propane to the form of power.


  1. January 6th, 2009
  2. January 6th, 2009
  3. January 6th, 2009
  4. January 6th, 2009
    Trackback from : GreenBldgBlog – Home
  5. January 6th, 2009
  6. January 6th, 2009
  7. January 6th, 2009
    Trackback from : Shower in the Dark
  8. January 6th, 2009
  9. January 6th, 2009
  10. January 6th, 2009
  11. January 6th, 2009
  12. January 6th, 2009
  13. January 6th, 2009
  14. January 6th, 2009
  15. January 6th, 2009
  16. January 6th, 2009

Best Green Blogs Eco Friendly, Environment & Green Blogs - Blog Catalog Blog Directory Environment Blogs Green Top Sites - Ranking the Best Green Sites on the Internet Renewable Energy Topsites Promote Your Blog