Before determining how much money you can save by taking a shower versus a bath, you must consider a few factors. The type of shower head, the length of time it takes you to shower and the cost of the water all must be considered. After you determine your water consumption, you can calculate how much you save — if anything — by taking a shower rather than a bath.
Whether you can save money by switching to a shower instead of a bath depends upon the length of time you spend in the shower.
Restricted — or low-flow — shower heads use half the water that traditional, unrestricted shower heads use. Low-flow shower heads only use about 2.5 gallons of water each minute. Unrestricted shower heads can use as much as twice that volume of water. If you have a home that was built before 1992 and you have never replaced the shower head, you have an unrestricted shower head.
Length of Bathing Time
The time you spend taking a shower will affect the cost of a shower when determining the relative cost of getting clean. A bath usually requires 20 to 50 gallons of water depending on how full you have the tub. The average shower can take about four minutes, but it might take longer if you're shaving or washing your hair.
If you shower with a restricted shower head that only uses 2.5 gallons of water per minute and lasts for four minutes, you will use 10 gallons of water versus a bath, which generally requires at least 20 gallons of water. If you take a shower every day for one year and use 10 gallons of water each time, you will use 3,650 gallons of water per year versus 7,300 gallons per year if you take a bath every day.
Cost of Water
The cost of water plays into the equation when determining the cost savings of bathing versus showering. Water companies measure water usage in cubic feet. One cubic foot is 7.48 gallons of water. If you use 3,650 gallons of water per year for a shower, you are using 487.97 cubic feet of water.
Although each municipal water utility has a different cost per cubic foot of water, the City of Sheboygan Water Utility has a cost of $1.50 per 100 cubic feet for the first 5,000 cubic feet. Therefore, 487.97 cubic feet of water used for a daily shower each year would cost about $731.96 per year. A year's worth of daily baths that use a total of 7,300 gallons — or 975.93 cubic feet — of water would cost about $1,463.90 per year.