How many times a day is the shower run at your home? How long is each shower? A shower can be a great way to unwind after a long day of work or school. It can also be a major source of water use. The amount of gallons of water per shower depends on two things: the shower head flow rate, and the amount of time spent showering.
Knowing the gallons per minute (GPM) that each shower head allows is the first step in calculating gallons of water per shower. If you do not know the amount, a flow meter bag helps you figure it out. Simply place the bag under the shower head, and allow it to run for a timed period. The markings on the bag will show you the flow rate of your fixture. From there, you can calculate the gallons of water per shower, and decide what fixture changes are necessary.
If you already know how many gallons of water per minute(GPM) your showerhead uses, a shower timer will help you keep track of the amount of time being spent in the shower. The timer is easily placed on the shower wall. From here, you can watch your shower use in 5-minute intervals. Once you know how long you have been in the shower, calculating overall shower water usage is fairly simple. As an example, let’s use a 1.5 gpm shower head for a family of four in which each person takes one 10-minute shower every day.
- Multiply the amount of water coming out of the shower every minute by the amount of minutes that one person spends showering to figure out shower water usage per shower: 1.5 x 10 = 15
- Multiply that number by the amount of people showering to see how much shower water is used every day: 15 x 4 = 60
- Multiply this by 7 (the amount of days in a week) to calculate weekly usage: 60 x 7 = 420
- Multiply weekly use by 52 (number of weeks in a year) to get annual shower water usage.
The chart below shows the amount of water being used by other shower heads.
Saving water in the shower starts with knowing how many gallons of water per shower are being used. Having this knowledge allows you to then change (whether in amount of time spent showering, or the fixture itself) shower water usage at home.