Busting Myths About Water-Efficient Toilets

Fact: Many ace CR’s lab tests.

Nearly all of the 60 toilets in CR’s current ratings use 1.28 gallons per flush or less, meeting the EPA’s strict WaterSense designation. And most stand up to CR’s rigorous lab testing.

To evaluate toilets, CR’s technicians flush varying volumes of items down their drains, including plastic balls, soaked sponges, and water-filled latex condoms. The toilets that perform best send simulated waste down in one flush and leave little residue on the front or sides of the bowl.

While some toilets outperform others, most models in our ratings deliver very good to excellent performance when it comes to solid waste removal, and the differences in scores don’t correspond to how much water they use.

Dual-flush toilets, which offer both high- and low-water flush options, use even less water in their low-volume setting (for liquid waste), allowing you to save even more without fretting about clogs. The American Standard Colony 3 and Glacier Bay models below are the highest-rated single- and dual-flush models in our ratings, respectively. Both are WaterSense certified.

Fact: Usually, one flush does it. 

Many toilets in our ratings, including low-flow models, can remove simulated solid waste in just one flush. That’s because water isn’t the only factor when it comes to effective flushing—or what sets apart good and poor performers.

Other design elements matter more, like whether the toilet relies solely on gravity or is pressure-assisted, the direction and force of the water that jets into the bowl, and even the shape of the bowl.

It’s important to note, too, that using too much toilet paper can cause even a high-performing toilet to clog. “Anyone trying to flush half a roll of toilet paper down at once is going to have an issue,” Halevah says. (If you do experience a clog, don’t just flush repeatedly. Turn to a plunger, a bowl or enzyme cleaner, or when all else fails, a plumber, our experts say.)

Fact: Not really.

Water-efficient models range widely in price. The least expensive single- or dual-flush option in our ratings—the $92 Toto Drake CST775CSFG-01—flushes with the same 1.28 gallons as the most expensive, the Toto Drake II CST453CEFG, just over $800. You can easily find well-rated, efficient models, both single- and dual-flush, for less than $200.

That’s not to say there aren’t big price differences in toilets. A high-style throne from a well-regarded brand, a wall-mounted model, or a smart toilet will set you back significantly. On its own, though, water efficiency doesn’t cost you more.

And a new, more efficient toilet can save you money in the long run. Upgrade from an older, inefficient toilet to a WaterSense-certified model, and you can save about $170 per year on your water bill, according to the EPA. That’s roughly $3,400 over the toilet’s lifetime. And if every older toilet in the country were replaced with a higher-efficiency model, the U.S. would save 260 billion gallons of water per year, equivalent to the water used in 16.25 billion showers.