Best 1 GPF and Ultra Low Flow Toilets

The Aquia IV is the ultra low flow toilet most buyers should start with, because its 0.8 gallon partial flush pulls the household average to the floor while its 1.28 gallon full flush still posts a perfect 1,000 gram MaP score, so you save the most water without ever sacrificing a clean clear.

The Aquia IV pairs a very low 0.8 gallon partial flush for liquids with a 1.28 gallon full flush for solids, and because most uses in a normal day are liquid only, that 0.8 gallon light flush drags the real-world average well under 1.0 gallon, which is the entire point of going ultra low flow. The full flush reaches a perfect 1,000 gram MaP score using TOTO's Dynamax Tornado swirl, which feeds water through twin nozzles to scrub the bowl in a centrifugal motion rather than dumping it down the front, so solids clear in one push despite the low volume.

The skirted two-piece body has smooth sides with no contoured trapway bumps to scrub, and the CeFiONtect glaze keeps the bowl cleaner between wipes. Owner reviews run deep and consistently praise the strong rinse and quiet refill, with the usual note that the top push-button takes guests and kids a moment to learn, which matters because the savings only show up if the small button actually gets used. For a household chasing the lowest meter reading, this is the default ultra low flow choice, and it also leads our roundup of the best water saving toilets of 2026.

The Niagara Stealth is the rare toilet that hits a flat 0.8 gallons on every single flush, with no buttons to learn, by using a sealed vacuum-assisted system that gives a low water volume the pull of a much larger flush.

The Stealth uses a vacuum-assist mechanism hidden inside the tank, sealing a chamber so that when you flush, the partial vacuum pulls water and waste through the trapway with far more force than 0.8 gallons would otherwise carry. That engineering lets it post an 800 gram MaP score on the lowest flat volume in this guide, clearing solids in a single push without any dual flush button to teach the household. Because every flush is 0.8 gallons, there is no way to accidentally use more water.

Owner reviews praise the genuinely tiny water use and the quiet, fast flush, with the recurring caution that the vacuum system needs adequate supply pressure to seal and refill properly, so it suits homes with normal water pressure better than those on a weak well or a high floor. The brand is a value name rather than a premium one, and the styling is plain, but for a buyer who wants the absolute lowest single flush with no behavior change required, nothing here goes lower. It is a natural fit alongside the picks in our guide to the best low flow toilets (1.28 GPF and under).

The San Souci is Kohler's compact, low-profile one-piece, and its dual flush drops to a 0.8 gallon light flush, giving a striking modern silhouette real ultra low flow savings with the brand's easy nationwide parts support.

The San Souci uses Kohler's AquaPiston canister flush in a dual flush configuration, releasing water into the bowl from all sides for an even rinse, with a 0.8 gallon partial flush for liquids and a 1.28 gallon full flush rated at a 600 gram MaP score. That 600 gram figure handles a typical home cleanly, and the appeal here is the rare combination of that ultra low water use with one of the most compact, sculptural one-piece bodies on the market, sitting low and seamless with a hidden trapway that wipes clean in one pass.

Because Kohler is sold in every big-box store, replacement seals and fill valves are easy to find locally for years, and the canister valve seals more reliably over time than a cheap flapper. Owner reviews praise the looks, the quiet flush and the easy cleaning, with the note that the 600 gram MaP, while plenty for a normal household, sits below the 800 to 1,000 gram leaders, so a home with very heavy waste loads may prefer a stronger flush. For a buyer who wants ultra low flow savings to live inside a genuinely good-looking fixture, the San Souci is the standout, and it features among the best eco friendly toilets for a greener bathroom.

The St. Tropez delivers a market-low 0.8 gallon light flush in a sleek skirted one-piece at a price well below the premium brands, making it the value way into true ultra low flow.

The St. Tropez pairs a 0.8 gallon partial flush, among the lowest available anywhere, with a 1.28 gallon full flush that reaches an 800 gram MaP score, so it clears solids cleanly without pressing the button twice. Its appeal is the combination of that very low water use with a contemporary low-profile design and a fully skirted base that wipes clean in seconds, all at a value price. The soft-close seat and the button plate are included, which keeps the package complete out of the box.

Swiss Madison is a newer brand than the established names, so its long-term reliability record and parts depth are not as deep, and a few owners note the compact tank can refill a little slowly between flushes, which is worth knowing on a home with modest supply pressure. Owner reviews are broadly positive on looks and flush strength, with the usual caution to confirm the bolt-down and supply connection on install. For a water-minded buyer who also wants a modern look without the premium price, it is the value pick of the ultra low flow field.

The Wellworth dual flush is Kohler's value workhorse, bringing a low 1.1 gallon partial flush and a strong full flush to one of the lowest prices in the category with the brand's easy nationwide parts.

The Wellworth dual flush uses a 1.1 gallon partial flush for liquids and a 1.6 gallon full flush for solids, with the full flush reaching an 800 gram MaP score through Kohler's Class Five system, which moves a large mass of water for a strong, fast clear. Its partial flush is not the lowest here at 1.1 gallons, but because most daily uses trigger that small flush, the household average still lands comfortably in ultra low flow territory, and it does so from a brand and a flush system with a long, dependable track record.

Because Kohler is everywhere, replacement seals and dual flush valves are easy to find locally for years, which is a real advantage over boutique brands. Owner reviews are deep and steady, praising the reliable flush and the budget price, with the note that it is a plainer two-piece without a skirted body, so the seam and base contours need occasional wiping. For a buyer who wants ultra low average water use from a trusted major brand on a tight budget, the Wellworth dual flush is the smart-money choice.

The T-0019 is Woodbridge's skirted designer one-piece, offering a body that looks far more expensive than it costs with a 1.0 gallon dual flush light mode for genuine ultra low flow savings.

The T-0019 is a fully skirted one-piece, so the trapway hides behind a smooth side panel and the seamless body wipes clean in one pass. Its dual flush uses a 1.0 gallon partial flush for liquids and a 1.6 gallon full flush that posts an 800 gram MaP score, enough to clear solids in one push, so the daily average lands in ultra low flow territory while the styling stays upscale. The soft-close seat is included, a genuine bonus at this price, and the comfort-height elongated bowl suits most adults.

Owner reviews run deep and consistently praise a clean flush, a quiet refill and the premium skirted shape that hides the trapway entirely. The tradeoff is that Woodbridge parts are less universal than TOTO or Kohler, so a repair may mean ordering a specific mechanism rather than grabbing a generic one, and the brand sells under several similar model numbers, so confirm the exact number and the dual flush volumes before ordering. For designer styling with real water savings, it is a standout pick and a regular feature among the best eco friendly toilets for a greener bathroom.

The H2Option is the dual flush pick for buyers who refuse to give up clearing power, pairing a 1.0 gallon partial flush with a full flush that reaches a 1,000 gram MaP score, the practical ceiling, at the WaterSense water limit.

The H2Option uses a 1.0 gallon partial flush for liquids and a 1.28 gallon full flush that posts a 1,000 gram MaP score, the highest in this guide, driven by a wide 3 inch flush valve that dumps water into the bowl fast and hard. That makes it the rare ultra low flow toilet that clears heavy loads as forcefully as a dedicated power model, so a home with demanding waste loads gets the lowest practical water use without ever risking a second flush. The full flush still sits at the 1.28 gallon WaterSense limit, so the savings are certified, not just claimed.

The fully glazed EverClean trapway resists the buildup of stains and odor-causing bacteria, so the bowl stays fresher between cleanings, and the ten-year limited warranty is among the longest in the category. It is a comfort-height elongated two-piece with practical styling, so the seam and base need occasional wiping, and the fast flush is a touch louder than a slow siphonic rinse. For a buyer who wants the strongest possible flush while still cutting water to the bone, the H2Option is the clear power choice, and a frequent pick in our roundup of the best EPA WaterSense certified toilets.

The Avalanche is Gerber's value dual flush toilet, a plumber favorite that delivers genuine low-water savings and dependable clearing for one of the lowest prices in the category.

Despite its low price, the Avalanche posts an 800 gram MaP score on its 1.6 gallon full flush with a wide glazed trapway, so it resists clogs about as well as toilets that cost far more, while its 1.1 gallon partial flush keeps the household average down in ultra low flow range for the many liquid-only uses each day. For a hardworking or rental bathroom where low-water savings are the goal and budget is tight, that combination of strength and value is hard to beat.

Gerber is a long-time plumber favorite because its toilets are dependable and inexpensive to service, and the simple two-piece design installs with standard fittings. The 1.1 gallon partial flush is not the lowest here, and the styling is plain with an exposed trapway, but for raw low-water value per dollar the Avalanche is the smart-money contractor choice, much like its siblings in our guide to the best water saving toilets of 2026.