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Read the guideA dual flush toilet gives you two buttons so you spend 0.8 gallons on liquid waste and 1.28 gallons on solids instead of 1.28 every single time. We ranked the best dual flush toilets using MaP flush-test scores, partial and full flush GPF, EPA WaterSense certification, trapway design, button valve quality, and patterns across thousands of aggregated owner reviews.
Research updated June 2026.
The TOTO Aquia IV is the best dual flush toilet overall: its Dynamax Tornado system drives a 0.8 gallon partial flush and a 1.28 gallon full flush that clears solids at 800 grams MaP without double pressing. For a budget skirted alternative, the Woodbridge T-0019 scores 1000 grams MaP on the full flush. The American Standard H2Option is the strongest full flush at its price, a consistent 1000 gram MaP performer.
Most toilet flushes in a home are for liquid waste. A standard 1.28 gallon single-flush toilet spends the same water volume every time regardless. A dual flush toilet splits that into two modes: a smaller partial flush for liquid-only waste and a stronger full flush for solids. Because liquid uses outnumber solid uses several times over across a typical day, the household daily water draw of a well-designed dual flush model runs meaningfully lower than an equivalent single-flush design, which is why EPA WaterSense actively promotes the category.
The failure mode of a poorly executed dual flush toilet is exactly the opposite of its promise: a weak full flush that requires two pushes, which uses more water than a single flush model ever would. That is why MaP score on the full flush is the most important number when choosing a dual flush toilet. We required an 800 gram MaP minimum on the full flush for every pick below. For the broadest look at performance across all toilet types, see our guide to the best flushing toilets.
We compare published manufacturer specifications, MaP (Maximum Performance) flush-test scores, EPA WaterSense certification status, and the patterns in thousands of verified owner reviews. For this category we weighted four factors above all else: full-flush MaP gram score, partial flush volume, flush mechanism and button valve quality, and owner-reported reliability over multiple years. Picks with sub-800 gram full flush scores, chronic leak reports tied to dual flush valves, or inconsistent bowl clearing did not make the list. We do not accept payment for placement.
| Toilet | Best For | MaP Score | GPF (Partial / Full) | Rating | Check Price |
|---|---|---|---|---|---|
| TOTO Aquia IV | Best overall | 800 g | 0.8 / 1.28 | 4.7 | Check price |
| American Standard H2Option | Strongest full flush | 1000 g | 0.92 / 1.28 | 4.6 | Check price |
| Woodbridge T-0019 | Best skirted one-piece | 1000 g | 1.0 / 1.28 | 4.5 | Check price |
| Kohler Cimarron Dual Flush | Best two-piece value | 800 g | 0.8 / 1.28 | 4.5 | Check price |
| Swiss Madison St. Tropez | Best modern design | 800 g | 0.8 / 1.28 | 4.4 | Check price |
| Gerber Avalanche Dual Flush | Best contractor pick | 800 g | 1.0 / 1.28 | 4.3 | Check price |
| TOTO Aquia IV Cube | Best for minimalist baths | 800 g | 0.8 / 1.28 | 4.6 | Check price |
| Kohler Highline Dual Flush | Best budget WaterSense | 800 g | 1.0 / 1.28 | 4.4 | Check price |

The Aquia IV is the dual flush toilet to recommend first because it ties the lowest widely available partial flush to a Tornado-powered full flush strong enough that double pressing is genuinely rare, all inside a clean skirted two-piece body from the brand that defines flush consistency.
The Dynamax Tornado flush feeds water through two angled nozzles that create a swirling bowl rinse rather than a front-dropping waterfall. That centrifugal action lets 1.28 gallons reach an 800 gram MaP score on the full push while the 0.8 gallon partial flush is at the bottom of what is commercially available. Because a typical household presses the small button far more than the large one, the math on annual water savings is real.
Owners consistently describe single-push solid clearing, quiet refill, and no running-toilet complaints linked to the valve. The fully skirted body eliminates the exposed trapway crease that traps grime on traditional two-piece designs. TOTO's CeFiONtect ion-barrier glaze adds surface resistance to mineral and waste adhesion. The main criticism across reviews is the learning curve of the top-mounted push button for first-time guests, but the mechanism itself is mechanically reliable in multi-year ownership reports.
When someone asks which dual flush toilet to buy without a specific budget constraint, the Aquia IV is the default answer. The 0.8 gallon partial flush is not just a marketing number: in a four-person household the partial savings add up to thousands of gallons per year over a 1.6 GPF baseline. The Tornado system means you are not trading water savings for flush power. Buy this one and you solve both sides of the problem.

The H2Option is for households that want dual flush water savings without any doubt about whether the full push will clear solids, posting a 1000 gram MaP score at 1.28 GPF, which is the highest full-flush grade in this roundup and matches dedicated high-performance single-flush models.
American Standard's VorMax technology uses a specifically angled jet to direct water around the full rim of the bowl before the siphon draws it down, which is partly why the H2Option achieves a 1000 gram MaP full-flush rating that matches models like the American Standard Champion 4 but at 1.28 rather than 1.6 GPF. The 0.92 gallon partial flush is slightly above the 0.8 minimum of the top tier, but for families worried about a weak full push, the 1000 gram score makes that trade reasonable.
Owner reports emphasize the reliable single-pass solid clearing, a quiet flush cycle, and the five-year limited warranty, which is longer than most competitors in the dual flush category. The two-piece construction is conventional to install and repair. The VorMax bowl design cleans better under the rim than a standard rim-wash geometry, reducing the visible buildup that gathers in corners.
If you have a large family or a shared bathroom that sees heavy use and you want dual flush savings without ever second-guessing the full push, the H2Option is the right call. A 1000 gram MaP score on a 1.28 GPF dual flush toilet is not a typical combination, and the five-year warranty adds genuine long-term value. If you want the absolute lowest partial flush, the Aquia IV wins; if you want the strongest full flush, this one does.

The Woodbridge T-0019 delivers a 1000 gram MaP full flush score and a clean skirted elongated one-piece design at a price well below comparable TOTO or Kohler options, making it the strongest-flushing skirted dual flush toilet per dollar in this roundup.
The T-0019 is Woodbridge's top dual flush model and its siphon jet achieves a 1000 gram MaP score on the full push, clearing heavy loads cleanly in a single flush. The 1.0 gallon partial flush is higher than the TOTO Aquia IV's 0.8 minimum, but the full flush power more than compensates, particularly for households that use both buttons regularly. The fully skirted one-piece body is a genuine advantage: there is no tank-to-bowl seam, no exposed trapway crease, and no secondary bolts to re-tighten over time.
The soft-close toilet seat is included, which reduces the upfront package cost compared to brands that sell the seat separately. Owner reviews note the flush mechanism is robust and the push button plate is firm rather than mushy. The main limitation is the 1.0 partial flush volume: buyers wanting the absolute lowest liquid-mode water use should choose the Aquia IV instead. If your priority is easy cleaning and strong full-flush power at a mid-range price, the T-0019 delivers both. For more on this brand's lineup, see our roundup of the best toilets for home use.
The Woodbridge T-0019 is the pick for bathroom renovators who want a skirted one-piece without spending TOTO money. A 1000 gram MaP score is not common at this price in a dual flush design, and the fully skirted body with an included seat makes installation day much smoother. The 1.0 gallon partial flush is the only compromise versus the premium tier.

The Kohler Cimarron Dual Flush brings EPA WaterSense certification, a reliable Class Five flush system, and Kohler's extensive replacement parts network into a two-piece dual flush design at a price that undercuts most premium picks significantly.
The Cimarron Dual Flush uses Kohler's Class Five flush system, which moves water at high velocity through a large 3-inch flush valve to pull bowl contents down by siphon action. The MaP full-flush score of 800 grams is solid rather than class-leading, but consistent owner feedback notes reliable single-pass clearing for normal household waste. The 0.8 gallon partial flush matches the lowest available in this category. WaterSense certification confirms that the combined flushing average falls within EPA efficiency thresholds.
Kohler's wide retail and parts distribution is a meaningful practical advantage: flappers, fill valves, and seats are available at hardware chains everywhere, and the Cimarron design has been in production long enough to have a well-documented owner record across multiple years. This is a strong choice for rental properties, guest bathrooms, and anyone who prefers a straightforward two-piece with a familiar brand behind it. Owners considering related options can also browse our guide to the best toilets of 2026.
The Cimarron Dual Flush is the answer when someone needs dual flush water savings, Kohler build quality, and accessible parts but does not want to spend premium money. The 0.8 gallon partial flush and WaterSense certification check the efficiency boxes, and the Class Five system is proven. For rental properties or a second bathroom, this is one of the most practical picks in the roundup.

The Swiss Madison St. Tropez is the dual flush choice for buyers who want a low-profile, clean-line skirted one-piece aesthetic at a price below the premium Japanese brands, while still hitting 0.8 gallon partial flush efficiency and an 800 gram MaP full-flush score.
The St. Tropez has a contemporary silhouette with straight sides, a concealed trapway, and a flush button plate integrated cleanly into the top of the tank. The 0.8 gallon partial flush ties the Aquia IV for the lowest light-mode volume in this roundup, and the 800 gram MaP full-flush score meets the minimum threshold we required of all picks. Soft-close seat and supply line are included, which reduces the total package cost compared to brands that sell components separately.
Owner reviews emphasize the visual appeal and the straightforward installation, with most noting the flush is quiet and the refill is fast. The most common critical note is about the flush mechanism seal quality: a small subset of owners across review aggregators report a running toilet within the first year, which is the most common risk with dual flush valves generally. Swiss Madison has addressed this in more recent production runs, and the 1-year warranty covers mechanical defects. For buyers comfortable doing occasional minor adjustments, the design and water savings are strong arguments in its favor.
The Swiss Madison St. Tropez earns its place by hitting 0.8 partial flush and 800 gram full flush MaP in a design that looks genuinely modern without the premium price tag. The flush valve reliability record is slightly behind TOTO and Kohler across multi-year ownership data, but for a mid-budget renovation bathroom it is a legitimately strong choice when aesthetics matter alongside efficiency.

The Gerber Avalanche Dual Flush is a sturdy, no-frills two-piece with an 800 gram MaP full-flush score and a 1.0 gallon partial flush, built to the commercial-grade standard that makes Gerber a consistent choice for plumbers and rental property operators who prioritize reliability over styling.
Gerber's reputation in the trades rests on durability and simple mechanicals that are easy to diagnose and repair. The Avalanche Dual Flush continues that pattern: its internal components are standard and serviceable, the vitreous china body is thick-walled, and the 10-year limited warranty is the longest in this roundup by a significant margin. The 800 gram MaP full flush is sufficient for typical household loads and consistent across owner reports. The 1.0 gallon partial flush is above the premium-tier minimum of 0.8, but well within efficient territory.
Unlike consumer-targeted brands that lead with aesthetics, the Avalanche is a straightforward elongated two-piece with clean lines but no standout design feature. Plumbers who specify Gerber for rental installations cite the parts availability and the low callback rate. For families with large households, the similar Gerber Viper is also worth considering. See our guide to best toilets for large families for context on high-use-case picks.
If you are buying a toilet for a rental unit, a vacation property, or any space where low maintenance and long-term mechanical reliability matter more than design, the Gerber Avalanche Dual Flush is a smarter long-term choice than a budget consumer brand. The 10-year warranty is the most concrete guarantee in this roundup, and Gerber's trade presence means parts are easy to source when needed.

The TOTO Aquia IV Cube is the same Dynamax Tornado flush platform as the standard Aquia IV but with a sharp-cornered tank and bowl profile that suits contemporary bathroom design, making it the only dual flush toilet in this roundup that pairs a 0.8 gallon partial flush with genuinely architectural geometry.
Under the different exterior, the Aquia IV Cube uses the same Dynamax Tornado two-nozzle swirl system that earns the standard Aquia IV its flush reputation. The 800 gram MaP full flush, the 0.8 gallon partial flush, and the CeFiONtect glaze carry over unchanged. What changes is the silhouette: the tank has right-angle corners where the standard model has curves, and the bowl profile is sharper and more linear, which reads clearly as a design choice in a contemporary bathroom.
Owner reviews note that the flush performance is identical to the standard Aquia IV, so the decision comes down entirely to aesthetics and budget. The Cube carries a slight premium over the standard model for the design work. For buyers fitting out a modern primary bathroom where fixture appearance is a primary specification, that premium is well justified. This is also a strong pick for seniors who prefer a contemporary look without sacrificing the Aquia IV's comfort height and reliable clearing. See our roundup of best toilets for seniors for more comfort-height context.
The Aquia IV Cube is the answer when a client specifically asks for the Aquia IV's performance in a design that matches a modern tile, floating vanity, or angular mirror. The flush technology is identical so there is no technical trade-off, only a design premium. If the budget allows and the bathroom's style calls for it, this is an easy recommendation.

The Kohler Highline Dual Flush brings WaterSense certification and Kohler's Class Five flush technology into the most widely available and lowest-cost dual flush configuration in the Kohler lineup, making it the right pick for budget-conscious buyers who still want a proven brand behind the fixture.
The Highline is Kohler's flagship traditional two-piece shape, and the dual flush variant carries the Class Five flushing system that Kohler has refined over many production years. The 1.0 gallon partial flush is the same as the Woodbridge T-0019 and the Gerber Avalanche, above the 0.8 of the premium tier but meaningfully below what a standard single-flush 1.28 model uses on every push. The 800 gram MaP full flush score meets our minimum threshold and handles normal household loads without double pressing in the large majority of owner reviews.
The Highline's long production history means replacement parts, seats, and fill valves are among the most widely available in retail and online. The 1-year warranty is standard for the category. For a second bathroom, a guest bath, or a budget-forward primary bathroom where the priority is reliability and efficiency over design standout, the Highline Dual Flush is the most accessible entry point in this roundup from a brand with a proven track record.
The Kohler Highline Dual Flush is the right choice when budget is the primary constraint and you still want a WaterSense-certified model with a proven Class Five flush rather than an unknown brand's cheaper dual flush. The 1.0 partial flush is not as aggressive as the premium picks, but it still saves water on liquid uses, and the Kohler parts network means this toilet is genuinely easy to maintain over the long run.
The dual flush category has matured significantly. Early designs with budget valves and weak full flushes gave the category a bad reputation that the TOTO Aquia IV, American Standard H2Option, and Woodbridge T-0019 have effectively erased. The critical spec remains the full-flush MaP score: buy anything below 800 grams and you will double flush, which eliminates the water savings entirely. Every toilet on this list clears 800 grams or above. The next variable is the partial flush volume: 0.8 versus 1.0 gallon sounds small, but across a four-person household over a year the difference is measurable on a water bill.
A dual flush toilet has two separate water volumes controlled by a split button or handle. Pressing the smaller button (or lower half) opens a partial flush valve that releases less water, typically 0.8 to 1.1 gallons, which uses siphon action or a wash-only rinse to clear liquid waste. The larger button activates the full flush valve for a stronger flow, usually 1.28 gallons, to clear solid waste. The key hardware difference from a single flush is the dual flush valve or tower, which must seal reliably in both positions. Cheap valves are the main source of running-toilet leaks in this category.
MaP (Maximum Performance) testing is independent third-party flushing evaluation conducted by Canadian testing consultancy Veritec. It measures how many grams of solid waste a toilet can clear in a single flush. A score of 1000 grams is the maximum. For dual flush toilets, the MaP score reported is for the full flush only, since the partial flush is not designed for solid waste. An 800 gram minimum is the threshold we applied here. A 1000 gram score means the toilet can handle significantly heavier loads without a second flush, which is why the American Standard H2Option and Woodbridge T-0019 rank highly despite not having the lowest partial flush volume.
EPA WaterSense is a voluntary labeling program that certifies toilets using no more than 1.28 gallons per flush for single-flush models, or an equivalent average for dual flush designs. For a dual flush toilet to earn WaterSense certification, the manufacturer submits both flush volumes, and the program evaluates whether the weighted average (accounting for typical use ratios) falls within WaterSense limits. A WaterSense-certified dual flush toilet qualifies for rebates from many municipal water utilities. All picks in this roundup meet WaterSense criteria.
The lowest widely available partial flush in a standard dual flush design is 0.8 gallons, found on the TOTO Aquia IV, TOTO Aquia IV Cube, Kohler Cimarron Dual Flush, and Swiss Madison St. Tropez. The next common tier is 1.0 gallon, found on the Woodbridge T-0019, Gerber Avalanche, and Kohler Highline Dual Flush. The American Standard H2Option is slightly higher at 0.92. For a two-person household, the difference between 0.8 and 1.0 partial flushes over a year may be small. For a large family with many daily liquid flushes, a 0.8 gallon partial flush delivers meaningfully more savings.
Two-piece dual flush toilets (separate tank and bowl) are generally lower cost, easier to ship without breakage, and straightforward to repair since internal components are easily accessed through the tank lid. One-piece dual flush models (Woodbridge T-0019, Swiss Madison St. Tropez, TOTO Aquia IV Cube as a skirted two-piece variant) have no seam between tank and bowl, which eliminates one cleaning surface and can look cleaner. Skirted designs add a smooth side panel to the two-piece frame to hide the trapway. One-piece units are heavier and slightly more complex to install but are otherwise equivalent in performance terms.
The flush mechanism in a dual flush toilet is more complex than a single-flush flapper. Instead of one flap, a dual flush valve uses a tower or canister with two seating positions. The most common point of failure is the seal between the canister and the flush valve seat, which can degrade and allow water to trickle into the bowl silently, wasting more water than the toilet was designed to save. TOTO's Dynamax system, Kohler's Class Five system, and American Standard's VorMax system all have strong multi-year reliability records in owner reviews. Less established brands have more variable records on this specific component.
The American Standard H2Option and the Woodbridge T-0019 both score 1000 grams on the MaP (Maximum Performance) full flush test at 1.28 gallons per flush, which is the maximum grade and matches dedicated high-performance single-flush models. The TOTO Aquia IV, Kohler Cimarron Dual Flush, Swiss Madison St. Tropez, Gerber Avalanche, TOTO Aquia IV Cube, and Kohler Highline Dual Flush all score 800 grams, which is sufficient for normal household waste in a single full flush. For the highest solid-waste clearing capacity in a dual flush design, the H2Option is the top pick followed closely by the T-0019.
MaP (Maximum Performance) scores run from 0 to 1000 grams, where 1000 grams is the maximum tested. For a household toilet, a score of 600 grams or higher is generally considered acceptable, 800 grams is considered strong, and 1000 grams is class-leading. For dual flush toilets specifically, any full-flush MaP score below 800 grams is a risk because a toilet that requires two full flushes to clear solids uses more water than a well-designed single-flush model. The EPA WaterSense program does not directly specify a MaP minimum, but third-party recommendations and plumbing industry guidance consistently point to 800 grams as the practical lower bound for a reliable household toilet.
The Kohler Cimarron Dual Flush offers the best value among name-brand dual flush toilets: it pairs a 0.8 gallon partial flush, an 800 gram MaP full flush, and EPA WaterSense certification with Kohler's nationwide parts availability at a mid-range price. For buyers who want a skirted one-piece at a value price, the Woodbridge T-0019 is the stronger option, as it delivers a 1000 gram MaP full flush and includes a soft-close seat. The Kohler Highline Dual Flush is the lowest entry price with a trusted brand name for buyers on a strict budget.
The American Standard H2Option is the best dual flush toilet for clog prevention, combining a VorMax siphon jet full flush with a 1000 gram MaP score, the highest in this category, which means it can clear significantly heavier solid loads in a single push than 800 gram competitors. A 1000 gram MaP score on the full flush, combined with a wide trapway opening, is the primary specification that determines clog resistance. For families with heavy use or members who prefer more toilet paper, the H2Option's full-flush power is the most direct protection against the double-flush situations that create backup risk.
Yes, a properly functioning dual flush toilet with a 0.8 gallon partial flush saves meaningful water compared to a 1.28 GPF single flush model over typical household use patterns. Studies cited by EPA WaterSense show that toilets account for roughly 30 percent of indoor household water use. If approximately 75 to 80 percent of daily flushes are for liquid waste, using 0.8 gallons instead of 1.28 gallons for those flushes adds up to hundreds of gallons per month in a household of four. The savings are only realized, however, if the full flush is strong enough that double flushing for solids is rare, which is why MaP score on the full flush is the most important performance specification for this category.
Most dual flush toilets use a split oval button or two separate buttons on top of the tank. The smaller button (or smaller half of the split button) is the partial flush for liquid waste. The larger button is the full flush for solid waste. Some models use a label or different color to indicate which is which, but the size convention is nearly universal across brands including TOTO, Kohler, and Woodbridge.
Yes, aftermarket dual flush conversion kits replace your existing flush valve and handle with a dual flush tower and button plate. These are available for most standard 2-inch and 3-inch flush valve seats. The conversion typically costs under $30 and takes under an hour to install. However, the partial flush volume and clearing performance of a converted toilet depend entirely on the original bowl geometry, which was not designed around a dual flush system. A purpose-built dual flush toilet like the TOTO Aquia IV or American Standard H2Option will perform more consistently than a converted standard model.
A running dual flush toilet almost always indicates a worn or improperly seated dual flush valve seal. Unlike a single-flush flapper that sits flat on a simple ring, the dual flush canister or tower seal must seat correctly in two positions. If the seal degrades or the tower is slightly misaligned, water trickles silently into the bowl. Replacing the dual flush valve or the seal kit (available for most major brands) resolves this in most cases. This is the most common maintenance task specific to the dual flush design.
Dual flush toilets require slightly more specific replacement parts than a standard flapper-based single flush toilet. For brand-name models like TOTO, Kohler, and American Standard, the correct repair kits are widely available online and at plumbing supply stores. For less common brands, finding exact parts can occasionally be more difficult. Outside of the flush valve seal, internal components such as fill valves and supply lines are standard and no different from a single flush model.
In many municipalities, yes. Most local water utility rebate programs for toilet replacement require EPA WaterSense certification, which all picks in this roundup carry. Rebate amounts vary by location, typically ranging from $25 to $200 per toilet. Check your local water utility's website or the EPA WaterSense rebate finder to confirm eligibility for your specific address and the model you are considering.
Yes, reliably, for liquid waste only. The partial flush in a properly designed dual flush toilet is engineered to clear urine and paper without full siphon action. It moves enough water to rinse the bowl and carry waste through the trapway. Where a 0.8 gallon partial flush can occasionally leave residue is if the bowl geometry is shallow or water pressure is lower than typical. The best-reviewed models in this category, including the TOTO Aquia IV and Kohler Cimarron Dual Flush, have bowl shapes optimized for the partial flush volume.
For the partial flush, 0.8 to 1.0 gallons is the current efficient range. For the full flush, 1.28 GPF is the standard and the EPA WaterSense threshold. Some older dual flush designs used 1.6 GPF for the full flush, which negates most savings and is not recommended. A 0.8 / 1.28 GPF split is the most water-efficient widely available configuration. The 1.0 / 1.28 split is still meaningfully efficient and is typical of mid-range picks like the Woodbridge T-0019 and Kohler Highline Dual Flush.
Yes, provided the full flush MaP score is high enough to clear solids reliably in one pass. For a large family, the high volume of liquid-only flushes makes the partial flush savings significant, and a 1000 gram MaP full flush like the American Standard H2Option or Woodbridge T-0019 means solid waste is cleared without repeated pressing. For more context on heavy-use picks, see our guide to the best toilets for large families.
Both technologies save water versus old 3.5 GPF toilets, but they do it differently. A dual flush toilet uses two water volumes to optimize daily use, with savings coming from the partial flush. A pressure-assist toilet uses compressed air to deliver a more forceful single flush, typically at 1.0 to 1.1 GPF, which saves on every flush equally. For most residential users, a well-designed dual flush toilet with a 0.8 gallon partial flush saves more total water over a day than a 1.1 GPF pressure-assist model, because most daily flushes are liquid-only.
CeFiONtect is TOTO's proprietary ion-barrier ceramic glaze that creates an ultra-smooth surface on the bowl at the microscopic level, making it harder for waste, minerals, and bacteria to adhere. TOTO applies CeFiONtect to several Aquia IV variants and to most of its premium lineup. It is not a coating that wears off; it is baked into the ceramic surface. Not all dual flush toilets have it: Kohler, American Standard, Woodbridge, Gerber, and Swiss Madison do not use CeFiONtect, though some have their own proprietary glaze treatments.
Yes, provided the model is comfort height (also called chair height or ADA height), which places the rim at 17 to 19 inches from the floor, comparable to a standard chair. All eight picks in this roundup are available in or default to comfort height configurations. For seniors with limited hand strength, the push-button mechanism on most dual flush toilets is easier to operate than a side-lever handle. For more considerations on toilet features for older adults, see our guide to best toilets for seniors.
Two-piece dual flush toilets like the Kohler Cimarron Dual Flush, Kohler Highline Dual Flush, American Standard H2Option, and Gerber Avalanche Dual Flush are generally the easiest to install because tank and bowl ship and maneuver separately. One-piece models like the Swiss Madison St. Tropez and Woodbridge T-0019 are heavier and more awkward to position in a tight bathroom, though installation complexity is otherwise similar. All standard toilets require the same basic rough-in measurement (typically 12 inches) and supply connection.
Most dual flush toilets, like most residential toilets sold in the United States, are designed for a 12-inch rough-in, which is the distance from the finished wall to the center of the floor drain. Some models, including select Kohler and American Standard options, are available in 10-inch and 14-inch rough-in versions. TOTO Aquia IV is a 12-inch standard configuration. Always measure your rough-in before purchasing, as ordering the wrong size requires a return and delays installation.
The EPA WaterSense program estimates that replacing a pre-1994 toilet (3.5 GPF or higher) with a WaterSense-certified model can save a family of four roughly 13,000 gallons per year. Compared to a modern 1.28 GPF single-flush model, a 0.8 / 1.28 dual flush design with 75 percent of flushes on the partial mode saves approximately 1,400 to 2,000 gallons per year for a four-person household, depending on actual use patterns. Actual savings vary by household size, water pressure, and how consistently users choose the partial flush for liquid-only waste.
For most households, yes. The Dynamax Tornado flush system is more reliable over multi-year ownership than most budget dual flush valves, the 0.8 gallon partial flush is the lowest available, and the consistent 800 gram MaP full flush means double flushing is rare. The main advantage of the Aquia IV over cheaper options is the long-term valve reliability: a budget dual flush toilet that develops a running leak wastes more water over its life than a reliable 1.28 GPF single-flush model, eliminating the efficiency justification entirely.
Elongated bowls are roughly 2 inches longer front-to-back than round bowls and are considered more comfortable for most adults. Flush performance in a well-designed toilet does not differ significantly between bowl shapes, since performance depends on water volume, trapway diameter, flush valve design, and bowl geometry at the trapway exit rather than the overall bowl length. All eight picks in this roundup use elongated bowls. Round bowls save space and are sometimes preferred in small bathrooms.
The flush technology is identical: both use the Dynamax Tornado dual flush system with a 0.8 gallon partial flush and 1.28 gallon full flush achieving 800 grams MaP. The difference is purely aesthetic. The standard Aquia IV has curved, traditional tank contours. The Aquia IV Cube has a sharp-cornered, angular tank and bowl profile that suits contemporary and modern bathroom design. The Cube carries a slight price premium. CeFiONtect glaze is available on both.
Skirted toilets have a smooth panel covering the trapway on the outside of the bowl, while non-skirted (standard) designs expose the curved trapway contours. Skirted designs are significantly easier to clean because there are no nooks for grime to collect. They also look more contemporary. The trade-off is a slightly higher price and, in some cases, floor-mounted bolts that are proprietary rather than standard. If cleaning speed matters and budget allows, a skirted design like the Woodbridge T-0019 or Swiss Madison St. Tropez is the practical preference.
The TOTO Aquia IV is the best dual flush toilet for most households, combining the lowest widely available 0.8 gallon partial flush with an 800 gram MaP Tornado full flush that clears solids reliably in a single press. For maximum full-flush power, the American Standard H2Option reaches 1000 grams MaP at 1.28 GPF, the highest score in this roundup, and brings a five-year warranty. Budget-conscious buyers get the most brand credibility per dollar from the Kohler Cimarron Dual Flush, while the Woodbridge T-0019 is the strongest skirted one-piece option. Every pick on this list carries EPA WaterSense certification and clears at least 800 grams MaP, so whichever you choose delivers real water savings without the double-flush frustration that gave early dual flush designs a bad name.
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