This post was updated on 2/14/2021
I’m a bath addict, but I also take showers when I wash my hair. Anyway, I often wonder if my bath vs. shower water usage is really that different.
On average, a shower uses less water than a bath. Bath takers use an average of 25-35 gallons of water, while a 10-minute shower with a regular showerhead will fill the tub with 25 gallons. However, a landmark study proved that shower takers spend longer in the shower than they report, and therefore, use more water than they think.
While we can talk in generalities, read on to figure out your bath vs shower water usage. First, we’ll look at population averages, and then I’ll show you how to calculate your personal bath vs shower water usage.
Bath vs. Shower Water Usage
Most bath takers will fill the tub with about 25-35 gallons of water.
A regular showerhead spills out 2.5 gallons-per-minute. If you are still using one of these types of showerheads, you’ll need to shower for 10 minutes to fill the tub with 25 gallons of water.
However, many households now use a low-flow showerhead. Most of these put out 2 gallons-per-minute. You’d need to shower for 12 minutes and 30 seconds to fill the tub with 25 gallons. And some really big earth lovers have installed showerheads that are even lower flow than that. (If you’re an earth lover, be sure to check out my tips for how to create a truly eco-friendly bathroom. You’ll conserve energy and money.)
Therefore, judging purely by the impact on the environment, I have to admit, a shower could be more efficient. But generalities and averages will only get you so far.
American Bathing Habits
Angie’s List surveyed 2,000 Americans about their bath and shower habits. While 66% of respondents bathe or shower daily, 20% take to the water to get clean every other day. A solid 45% of shower takers reported that they spent 5-10 minutes running the water, 28% of bath takers reported spending 10-20 minutes in the tub.
So where does this leave us in our quest to understand your own water usage?
Don’t Believe Shower Takers
First of all, don’t believe everything you hear—especially from shower takers. They are likely to tell you (perhaps a bit self-righteously) that they spend quite a bit less time on their cleaning ritual than bath takers.
It was a study by Unilever that confirms that people who shower can’t be trusted to report their own time. That’s right! You can’t trust a person who prefers showers to baths. Not for a second.
UK Bathing Habits
The 2011 landmark UK Sustainable Shower Study looked at 2,600 unique shower experiences that were taken over 10 days by members of 100 families. A sensor placed in the shower measured the duration of experience, while each study participant completed a “shower diary.” In the diaries, subjects reported how long they thought each shower took.
Despite reporting 5-minute showers, the study found that average shower length for participants was 8 minutes, revealing their judgment was off by more than 50%! In fact, a key finding of the study is as follows: The shower uses nearly as much energy and water as a bath.
Bath vs. Shower: Personal Water Usage
I’m not saying that people who soak in the tub are more virtuous. Only that they don’t fib. Or at least if they do, it hasn’t been studied yet. The best thing to do when trying to compute your actual environmental footprint is to study your personal habits as objectively as possible. That way you’ll get accurate data for your personal bath vs. shower analysis.
Follow these steps to calculate whether you, personally, use more water for a bath vs. shower:
- Plug the drain.
- Take your normal shower.
- Mark how high the water is in the tub with a piece of tape.
- Drain the water.
- Next time you fill the tub to take a bath see if the tape is higher or lower than the tub water.
This should give you a good sense of whether you typically use more water for a bath or shower. However, this is not a double-blind study and your bias can impact the outcome. For example, if you want to hear that your short showers are doing a service to the earth, during the test, you might abbreviate your shower more than you normally do.
You will also want to consider how often you bathe or shower. If you shower daily but bathe only every other day, then you could be saving water by bathing instead.
Comparing Apples to Oranges
In some ways, comparing baths to showers is similar to comparing apples to oranges: You might eat an apple because you need some crunch, and they are in season. But you might choose an orange for hydration after a sporting event. Similarly, you might decide to take a shower for an altogether different reason than you decide to take a bath.
The impact of bath vs. shower on the earth is one consideration. And the impact of your shower or bath on your entire life is another.
While a shower might serve to purely dash and go, your reasons for bathing might be a lot more involved: After all, research shows that baths can be taken to achieve everything from weight loss to the alleviation of depression.
How to Measure Bath vs Shower Water Usage
There are a number of devices on the market designed to help you calculate your water usage when bathing or showering. The idea is that if you’re truly aware, then you can take steps to reduce.
There are various waterproof shower timers on the market. These help you limit your water usage in the bath or shower. Some are hourglasses with sand that will suction to the wall and run down for 5 minutes. There are other innovations like the Waterpebble that you place on the bottom of the shower and it will turn red when a preset amount of time is up. None of these has outstanding reviews, so I’d suggest going with a regular waterproof timer like this one by dretec.
This is a device installed on your home’s main water line. It’s designed to detect leaks anywhere in your house. The Flume Water Monitor comes with an app that can alert you any water problems before you would see them with your own eyes. And best of all, it helps you measure water use in your home, both inside and outside, moment by moment. You can check the app to see if there’s an unusual spike in water use. This can alert you to the fact that your teenager is about to overflow the bathtub or has been in the shower for thirty minutes and counting.
3 Devices to Help You Conserve Water
There are smart gadgets coming out every day to help you conserve your water use. Here are 3 of my favorite gadgets to help you conserve water:
Tankless Water Heater
Unlike a conventional water tank that stores and heats a preset amount of water regardless of whether it will be used, a tankless water heater doesn’t store any water. And it only warms the water as it’s needed. This conserves energy and costs you less. How much do you conserve? According to energy.gov:
“For homes that use 41 gallons or less of hot water daily, demand water heaters can be 24%–34% more energy efficient than conventional storage tank water heaters. They can be 8%–14% more energy efficient for homes that use a lot of hot water — around 86 gallons per day. You can achieve even greater energy savings of 27%–50% if you install a demand water heater at each hot water outlet.”
This uniquely designed showerhead allows you to conserve water without compromising a bit on the shower pressure. It comes with a hose and adjustable arm mount. While you’ll get more spray to luxuriate in, you’ll actually be using 28% less water than you would with a regular showerhead as the Rua flows at 1.8 Gallons Per Minute. The elegant, lightweight design is simply gorgeous.
PerfectFill by Kohler
I’ve been waiting for someone to come out with a smart bathtub that will fill to a preset amount at a preset temperature with a simple voice command. Though not yet on the market, apparently, Kohler Smart Home has this in the works. You can click here, scroll down to the bathtub, and sign up to be notified the second that this innovation hits the market.
How to Recycle Bath and Shower Water
Help the environment by recycling your bath and shower water in both large and small ways. You can use gently used bath or shower water to fill your toilet tank. Or you can use it to water your garden.
There are high-tech and low-tech methods you can use. But either way, you’ll save money and water at the same time. That is a real win-win for reducing the environmental impact of both bath and shower. Curious to know more? Check out Reusing Bath Water is Not as Hard as You Think.
So Does a Bath or Shower Use More Water?
On average, we can say a bath uses slightly more water than a shower. But for you, individually, a shower might use more water. And if you recycle your used bath or shower water, then you’re doing much more for the environment than someone who doesn’t.
Is there a way to reuse my bathwater? Yes, bathwater is called ‘greywater’ because it can generally be repurposed for watering plants or flushing the toilet. The issue is how you will capture the water. According to Treehugger.com, there are several options including manually collect the water in buckets for reuse, or installing a 3-way valve to divert greywater to a grey water tank in your home. You can also use a sump pump and tube to pump bathwater out a window and into a barrel for use in the garden.
How else can I make my bathroom eco-friendly? Use compact fluorescent lights which will reduce energy use by 75%. Switch out your plastic shower curtain for a 100% recyclable, PVC-free, mildew-resistant hemp curtain. Also, consider using organic cleaning products and cleaning the air with an ionic filter. Choose natural materials like cotton, bamboo or hemp for bath mats and bath towels.