Best 1.0 GPF Toilets: Maximum Efficiency Options 2026

The TOTO Eco Drake uses exactly 1.0 gallon per flush yet posts a 1,000 gram MaP score, the ceiling of independent flush testing, by pairing a wide 3-inch flush valve, a fully glazed 2-1/8 inch trapway and TOTO's G-Max gravity system to move waste with far more force than its gallon count suggests.

The Eco Drake is TOTO's most proven two-piece toilet in its lower-volume configuration. Its G-Max system dumps water into the bowl through a wide 3-inch flush valve far faster than a standard 2-inch valve, creating a rush that carries 1,000 grams of solid material through the fully glazed 2-1/8 inch trapway in a single flush, despite using only 1.0 gallon to do it. The EPA WaterSense certification confirms the low volume and the performance are both verified, not just claimed. Because most of the flush power comes from the large valve opening and the bowl geometry rather than raw water mass, it resists clogs without the 0.8 gallon forced-siphon tricks that some smaller-volume toilets need.

Owner reviews across thousands of verified purchases consistently praise the reliable, powerful clear and the quiet refill, with the usual note that it is a two-piece with an exposed trapway that requires some seam wiping on cleaning day. The CeFiONtect ion-barrier glaze on TOTO models keeps the bowl cleaner between cleanings by preventing waste from adhering to the surface. If you are replacing an older high-gallon toilet and want the best possible clearing performance at 1.0 GPF with a trusted brand behind it, the Eco Drake is the default recommendation and features prominently in our roundup of the best EPA WaterSense certified toilets.

The Eco Ultramax packages the same G-Max 1.0 GPF flush system and 1,000 gram MaP score as the Eco Drake into a seamless one-piece body that wipes clean in seconds, making it the premium choice for a high-traffic or highly visible bathroom.

The Eco Ultramax's selling point is the seamless one-piece construction, which eliminates the seam between tank and bowl where grime accumulates on a two-piece toilet, and the hidden skirted trapway on most configurations, which removes the curved bump on the outside of the base that is the hardest part of any toilet to keep clean. The G-Max system underneath delivers the identical 1.0 gallon, 1,000 gram performance as the Eco Drake, so there is no performance penalty for the cleaner body. The CeFiONtect glaze repels waste and keeps the inside of the bowl cleaner between scrubs.

Owner reviews are among the most consistently positive in the 1.0 GPF category, praising the powerful quiet flush, the easy-to-clean body and the premium feel. The Eco Ultramax costs more than the Eco Drake because you are paying for the one-piece manufacturing and the cleaner exterior, and TOTO's 1-year limited warranty is shorter than American Standard's ten-year on some models, but the brand's long reliability record and consistent owner review scores suggest the toilet earns that through longevity. It sits beside the Eco Drake in our guide to the best TOTO toilets of 2026.

The Cadet 3 Flowise is American Standard's 1.0 GPF variant of its most popular flush platform, pairing a 1,000 gram MaP score with a 10-year limited warranty and wide hardware-store availability at a price below the TOTO options.

The Cadet 3 Flowise carries American Standard's wide 3-inch flush valve, which releases water into the bowl 125 percent faster than a standard 2-inch valve, generating the momentum that drives a 1,000 gram MaP score at just 1.0 gallon. The EverClean antimicrobial surface finish is glazed into the bowl at the factory rather than applied as a coating, so it resists the growth of bacteria, mold and mildew on the bowl surface for the life of the fixture. EPA WaterSense certified, with a ten-year limited warranty that is among the longest in the category.

Because American Standard sells through every major hardware chain, replacement flappers, fill valves and flush levers are genuinely easy to find locally at low cost for years after purchase, which is a meaningful real-world advantage over boutique brands. Owner reviews across a very large sample are consistently positive on flush reliability, clog resistance and the value-for-money equation, with the recurring caveat that the exterior is a plain two-piece with an exposed trapway rather than a designer shape. For a buyer who wants the best possible flush at 1.0 GPF from a mainstream brand with deep parts availability and a long warranty, the Cadet 3 Flowise wins this tier convincingly and ranks among the best options in our guide to the best American Standard toilets.

The Kohler Cimarron's 1.0 GPF configuration uses the AquaPiston canister flush valve to deliver water into the bowl from all 360 degrees, posting an 800 gram MaP score with a quieter, more even rinse than a single-direction flush valve at the same water volume.

Kohler's AquaPiston canister uses a full 360-degree opening that distributes water evenly around the bowl rim as it enters, giving a more thorough rinse with less of the concentrated forward-flush noise common to front-fed flush valves. The canister design also seals more reliably over time than a standard rubber flapper, since the piston seats on a wide gasket rather than a narrow edge, reducing the risk of the phantom flushing that a slowly leaking flapper causes. At 1.0 gallon and 800 grams, the Cimarron is a step below the 1,000 gram leaders, which is fine for most households but worth noting for anyone with a heavier-than-average waste load.

Because Kohler has the broadest big-box retail presence of any toilet brand, replacement canisters, fill valves and trip levers are available at local stores rather than requiring online ordering. Owner reviews run deep and positive, consistently praising the even, quiet flush and the tidy elongated profile, with a few notes that the 800 gram MaP should be considered against household needs. It sits alongside the Highline in our overview of the best Kohler toilets.

The Gerber Viper at 1.0 GPF is a plumber favorite that posts an 800 gram MaP score through a wide trapway, delivers reliable low-water performance at a competitive price point and carries a five-year limited warranty on the vitreous china.

The Viper's 1.0 GPF gravity system uses a fully glazed trapway that resists buildup and a well-proportioned flush valve to clear 800 grams in a single push, a strong result for a toilet at this price. Gerber has a long history as a trade-quality brand: the vitreous china is dense, the standard two-piece construction is familiar to any plumber, and the basic internals require no learning curve for repairs or replacements. For outfitting a rental property, a commercial tenant buildout or a multi-bathroom new construction, the Viper covers the 1.0 GPF efficiency requirement at the cost per unit that matters when you are buying several at once.

Owner reviews are practical and positive, noting reliable clears and low maintenance rather than premium aesthetics. The 800 gram MaP handles normal household use without requiring a second flush, and the wide glazed trapway is the main clog-resistance mechanism, which is straightforward and dependable. Where the Viper falls short is style: it is a plain two-piece with no design ambitions, so it belongs in a utility or rental bathroom, not a remodeled master suite. Its companion in the Gerber lineup appears in our guide to the best Gerber toilets.

The Woodbridge T-0001 is a fully skirted one-piece with a dual flush that reaches a 1.0 gallon small flush, offering contemporary design with genuine low-water performance and an included soft-close seat in a package that looks far more expensive than it costs.

The T-0001 uses a dual flush mechanism with a 1.0 gallon small button for liquids and a 1.6 gallon large button for solids, and the full flush posts an 800 gram MaP score. This makes it a dual flush toilet rather than a true single-flush 1.0 GPF design, which is an important distinction: the 1.0 gallon use only accumulates if household members consistently press the small button for liquid-only uses. When they do, the daily average drops well into efficient territory. The fully skirted body has smooth sides with no visible trapway contours, making it one of the easiest toilets in this guide to keep clean.

Owner reviews are strong on the aesthetics and the flush performance, with consistent praise for the premium skirted shape and the included soft-close seat that most comparably priced toilets sell separately. The main caution is parts: Woodbridge mechanisms are specific to the brand, so a worn flush button assembly requires a Woodbridge replacement rather than a generic hardware-store part, and owners should keep a spare on hand. For a buyer remodeling a bathroom who wants a contemporary, clean profile alongside 1.0 gallon partial flush efficiency, it is the best-looking choice in the guide and a repeat feature among our picks for best Woodbridge toilets.

The Swiss Madison Ivy is a compact skirted one-piece with a 1.0 gallon partial flush and a 700 gram MaP score, offering a slim modern silhouette and genuine water savings at a lower entry point than the TOTO or Kohler one-piece options.

The Ivy's 700 gram MaP score on its full flush is strong enough for a typical household, though a step below the 800 gram Kohler and Gerber picks and well below the 1,000 gram TOTO and American Standard leaders. The value proposition is the skirted one-piece construction at an accessible price, with a 1.0 gallon partial flush for liquids and a slim wall-hugging profile that suits compact bathrooms where fitting a bulkier tank would be tight. The included soft-close seat completes the package without requiring a separate purchase.

Swiss Madison is a younger brand with a shorter parts depth than the established names, so buyers should weigh that when considering long-term service. Owner reviews are broadly positive on aesthetics and flush quality, with the recurring note that the compact tank refills slightly more slowly than a larger-volume tank between flushes, which is worth knowing in a high-traffic bathroom. For a renovation buyer who wants a slim modern profile, a 1.0 gallon small flush and a complete in-box package without the premium brand premium, the Ivy is the right value call in this guide and features among the best Swiss Madison toilets.

The Kohler Highline in its 1.0 GPF configuration is the no-nonsense workhorse of the category, combining the brand's AquaPiston flush with 800 gram clearing power, universal local parts availability and one of the simplest installation footprints in the lineup.

The Kohler Highline is one of the longest-running and most widely sold toilet lines in North America, and the 1.0 GPF version retains the AquaPiston canister valve that distinguishes it from older flapper-based designs, delivering an even 360-degree water release that generates an 800 gram MaP score at the low 1.0 gallon volume. Its two-piece construction uses a standard 12-inch rough-in and follows a bolt pattern and supply connection that any plumber knows by memory, keeping installation and future service simple. The timeless Highline silhouette blends into any bathroom without announcing itself.

Owner reviews show some of the deepest and most consistent satisfaction scores in the category, driven by long-term reliability and the peace of mind that any worn part can be found at a local hardware store rather than requiring a brand-specific order. For the buyer who wants a dependable, well-supported 1.0 GPF toilet in the most recognizable workhorse form, the Highline is the answer, and its full family lineup is covered in our guide to the best Kohler Highline toilets.