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Read the guideA MaP score of 1,000 grams is the ceiling of the Maximum Performance flush test. Only the strongest toilets reach it, meaning they cleared a full kilogram of solid waste in one flush during independent laboratory testing. This guide ranks the top models that carry that verified rating and explains what separates them once the headline number is identical.
Research updated June 2026.
The TOTO Drake is the strongest all-around MaP 1000 toilet: maximum flush rating, 1.28 GPF, EPA WaterSense certified, 3-inch flush valve, and a near-universal availability of replacement parts. For households that demand sheer bulk-clearing capacity at a lower price, the American Standard Champion 4 delivers the same 1,000-gram score through an industry-leading 4-inch valve.
The Maximum Performance, or MaP, flush test was developed independently in 2003 by Veritec Consulting and IAPMO Research and Testing. It simulates real-world waste by dropping standardized soybean-paste media into a toilet bowl, flushing once, and recording the heaviest load the toilet clears completely. The scale runs from 100 to 1,000 grams. When a toilet clears 1,000 grams, the test does not continue because no realistic daily use exceeds that level. The score is a ceiling, not an open-ended measurement.
Most toilets sold today score between 400 and 700 grams, which is adequate for ordinary household use. A score of 800 grams is genuinely strong. A score of 1,000 grams means the toilet passed the hardest single-flush demand the independent protocol could throw at it. When two or more toilets carry that identical rating, the decision shifts to water consumption, flush valve design, trapway width, bowl height, warranty coverage, and the patterns in aggregated owner feedback. That is exactly what this guide does: separates the 1,000-gram field into a ranked list you can act on. For the full overview of top performers across all score levels, see our guide to the best flushing toilets.
A MaP 1000 score means a toilet cleared 1,000 grams of standardized solid waste media in a single flush during independent Maximum Performance testing, which is the highest result the protocol awards. The test uses soybean-paste cylinders that mimic the density and consistency of human waste, so the score reflects real-world clearing capacity rather than water volume alone. No toilet in normal residential use will ever approach that load, so a 1,000-gram-rated toilet effectively eliminates clogging as a practical concern.
The MaP protocol was created specifically because GPF ratings alone cannot predict clog resistance. Two toilets flushing at 1.28 gallons per flush can produce completely different results when tested with solid media, because the shape of the trapway, the size of the flush valve, the jet configuration, and the bowl geometry all determine how much pressure reaches the waste. GPF is a water-use metric. MaP is a performance metric. They measure different things, and a toilet that scores 1,000 grams under the MaP protocol has demonstrated maximum clearing performance regardless of how it achieves it.
Eight verified models carrying the maximum 1,000-gram MaP score, ranked by water efficiency, flush system design, and owner satisfaction.
| Toilet | Best For | MaP Score | GPF | Flush Valve | WaterSense | Check Price |
|---|---|---|---|---|---|---|
| TOTO Drake | Best overall | 1,000 g | 1.28 | 3 in | Yes | Check price |
| American Standard Champion 4 | Largest flush valve | 1,000 g | 1.6 | 4 in | No | Check price |
| TOTO UltraMax II | Best one-piece | 1,000 g | 1.28 | 3 in | Yes | Check price |
| American Standard Cadet 3 | Best budget pick | 1,000 g | 1.28 | 3 in | Yes | Check price |
| Kohler Cimarron | Best Kohler option | 1,000 g | 1.28 | 3 in | Yes | Check price |
| TOTO Drake II | Best two-piece upgrade | 1,000 g | 1.28 | 3 in | Yes | Check price |
| Woodbridge T-0001 | Best modern design | 1,000 g | 1.28 | 3 in | Yes | Check price |
| Gerber Viper | Best contractor pick | 1,000 g | 1.28 | 3 in | Yes | Check price |
The TOTO Drake has carried the maximum 1,000-gram MaP score across multiple tested configurations and remains the single most recommended toilet by plumbers, contractors, and independent plumbing reviewers in North America.
The Drake uses TOTO's G-Max flushing system, which routes water through a large 3-inch flush valve and directs it into a 2-1/8-inch fully glazed trapway. The geometry creates a powerful siphonic action that pulls waste through the trap efficiently at 1.28 gallons rather than the 1.6 gallons older designs needed. Published MaP results show the Drake clearing the maximum 1,000-gram media load cleanly, which means every realistic household use falls well within its confirmed capacity.
Owner reviews aggregated across major retailers consistently place the Drake among the top-rated two-piece toilets for reliability. The most common feedback themes are that the flush is noticeably stronger than previous toilets in the same home, that it has not clogged after years of use, and that parts are easy to source when the fill valve or flapper eventually needs replacement. The Drake's longevity as a top seller means the supply chain for components is deep and stable.
The TOTO Drake is as close to a default recommendation as exists in the residential toilet market. It has a track record long enough that its real-world failure modes are well documented and rare. The combination of maximum MaP rating, 1.28 GPF, WaterSense certification, and universal parts availability is difficult to match at any price point.
The American Standard Champion 4 is built around the largest consumer flush valve in mainstream production: a 4-inch EverClean surface-coated valve that opens a nearly complete water column over the bowl in a single motion, producing a forceful bulk-clearing flush that earned the maximum 1,000-gram MaP rating.
The Champion 4's flush mechanism works differently from most siphonic designs. The 4-inch tower-style flush valve drops the entire tank volume into the bowl almost simultaneously, creating a high-volume surge rather than the gradually accelerating siphon that most 3-inch valve designs rely on. Published MaP testing confirms this approach reaches the 1,000-gram ceiling at 1.6 GPF. The trade-off is water volume: the Champion 4 uses 1.6 gallons per flush compared to the 1.28 gallons of most competitors on this list.
For households with older drainlines, septic systems with partial blockages, or high-occupancy use where the toilet cycles frequently, that extra water volume can be an advantage rather than a waste. Aggregated owner reviews note fewer maintenance calls compared to previous toilets, with several reviewers specifically mentioning that the Champion 4 replaced a toilet that was clogging weekly. See our dedicated best flushing two-piece toilets guide for more two-piece comparisons.
The Champion 4 is the right answer when a household has a history of clogging and wants maximum mechanical force rather than water efficiency. The 4-inch valve is genuinely different from anything else in the consumer market, and the 1,000-gram MaP result reflects that. If water savings are not the priority, this is the most forceful gravity toilet available.
The TOTO UltraMax II brings the same 1,000-gram MaP-rated flush system found in the Drake into a single fused tank-and-bowl unit that eliminates the seam where grime and mold accumulate on two-piece designs.
The UltraMax II uses TOTO's Double Cyclone flushing system, which replaces the conventional rim holes found in most toilets with two nozzles that generate a powerful centrifugal water flow across the entire bowl. This design cleans the bowl surface more completely with each flush and directs water pressure toward the trapway exit rather than dissipating it across dozens of rim holes. The result is a 1,000-gram MaP score at 1.28 gallons per flush, which is the most water-efficient performance tier in this rating class.
Owners consistently cite the SanaGloss surface as a meaningful real-world benefit: the ionic barrier glaze reduces how often manual scrubbing is required to keep the bowl clean. Aggregated review data shows the UltraMax II receives high marks for aesthetics and cleaning ease alongside its flush performance, making it the preferred choice for master bathrooms and renovation projects where appearance and hygiene standards are high. For more one-piece options, see our best flushing one-piece toilets guide.
The UltraMax II is what you choose when you want maximum MaP performance without compromising on bathroom aesthetics or cleaning effort. The SanaGloss glaze is not marketing; it genuinely changes the surface chemistry in a way that reduces staining. If budget allows the upgrade from the Drake, this one-piece design rewards the investment.
The American Standard Cadet 3 FloWise reaches the maximum 1,000-gram MaP rating while using only 1.28 gallons per flush and carrying EPA WaterSense certification, making it one of the best-value entries in the maximum-performance category.
The Cadet 3 FloWise uses American Standard's Power Wash rim technology, which directs water around the entire rim on flush rather than through conventional holes, improving bowl coverage and scrubbing action. Combined with the fully glazed 2-1/8-inch trapway, it moves waste through the drain quickly enough to clear the 1,000-gram MaP media at 1.28 gallons per flush. The EverClean surface, treated with an antimicrobial silver-ion formula, is standard across the Cadet 3 line and keeps the bowl cleaner between scrubbing sessions.
Aggregated owner reviews highlight the Cadet 3's reliability record. It is one of the most installed toilets in North America, which means its failure patterns are well understood and parts are genuinely cheap and easy to source. For rental property owners and renovation budgets where multiple toilets need replacement, the Cadet 3's combination of maximum MaP rating and accessible price makes it the practical first choice. Compare it against TOTO in our Kohler Highline vs Cadet 3 breakdown.
The Cadet 3 FloWise punches well above its cost tier. Reaching the 1,000-gram MaP ceiling at 1.28 GPF with WaterSense certification is not easy, and American Standard delivers it at a price that makes it the correct answer for multi-unit replacements or anyone who wants maximum performance without overspending.
The Kohler Cimarron uses Kohler's AquaPiston flush canister, a 360-degree water-entry mechanism that replaces the conventional flapper with a canister that opens from all sides, pushing water into the bowl with greater force and coverage than traditional single-direction valve designs.
Kohler's AquaPiston canister mechanism is the key differentiator in the Cimarron. Standard toilet flush valves use a flapper that lifts and allows water to flow in one direction. The AquaPiston canister lifts straight up and exposes the valve from 360 degrees, releasing water equally in all directions into the bowl simultaneously. Kohler publishes independent MaP test results for the Cimarron showing it achieves the 1,000-gram maximum, which places it in the highest performance tier regardless of the mechanism's difference from conventional designs.
Aggregated owner reviews for the Cimarron consistently note satisfaction with flush power and bowl coverage. The Comfort Height specification at 17 inches above floor matches what most adults find comfortable for extended use and aligns with ADA accessibility guidelines. Kohler's warranty and service coverage make this a sound long-term choice for homeowners who prefer to stay within one brand's ecosystem across their bathroom fixtures.
The AquaPiston mechanism is a genuine engineering difference, not a marketing claim. The 360-degree water entry does produce measurably better bowl coverage than flapper-based designs of comparable valve size, which is part of why the Cimarron reaches the MaP ceiling at 1.28 GPF. For Kohler loyalists, this is the right model.
The TOTO Drake II is the updated successor to the original Drake, replacing the G-Max flushing system with the Double Cyclone system, which uses two nozzles rather than rim holes to generate a high-momentum rotational rinse of the bowl on every flush.
The key difference between the Drake and Drake II is the flush geometry. Where the original G-Max system uses conventional rim holes to distribute water around the bowl, the Double Cyclone system routes water through two large propulsion nozzles that create a rotating rinse pattern. TOTO's published testing shows the Drake II meets the 1,000-gram MaP ceiling, and owner reviews suggest the bowl stays visibly cleaner between scrubbing sessions because the rotational water motion covers the entire surface rather than relying on gravity rundown from rim holes.
The Sanagloss ionic-barrier glaze on the Drake II is the same technology TOTO applies to the UltraMax II, and it works identically: the glaze reduces the surface energy of the porcelain so that waste, mineral deposits, and bacteria have less adhesion. Aggregated reviews confirm that owners notice a real difference in how often scrubbing is required. The Drake II is the better choice when bowl hygiene is a priority alongside maximum flush performance. For a detailed comparison of these two TOTO models, see our TOTO Drake vs Drake II breakdown.
The Drake II is a meaningful improvement over the original Drake when bowl cleanliness matters. The Double Cyclone flush is more thorough across the bowl surface, and the Sanagloss glaze adds a layer of passive hygiene maintenance. For a two-piece toilet that combines maximum MaP performance with reduced cleaning effort, the Drake II earns the upgrade cost.
The Woodbridge T-0001 is a dual-flush skirted one-piece toilet with a fully concealed trapway and a modern rectangular profile that suits contemporary bathroom renovations while carrying the maximum 1,000-gram MaP flush rating.
The Woodbridge T-0001's fully skirted design means the external surface from tank to floor is a smooth flat panel with no visible curves or ridges. There are no exposed trapway curves to collect dust and grime, which reduces the effort required to keep the exterior clean. Published MaP results confirm the T-0001 reaches 1,000 grams on its full 1.28 GPF flush mode, while the 0.8 GPF half-flush handles liquid waste using significantly less water. The dual-flush button sits on the top of the tank in a recessed position that maintains the rectangular profile.
Owner reviews frequently mention the aesthetics as the primary reason for purchase and the flush performance as a pleasant confirmation. The main reported concerns involve the skirted design making it harder to access the base for repairs, and Woodbridge's service infrastructure being less developed than the major brands. For buyers renovating a contemporary bathroom who need genuine top-tier flush performance in a modern form, the T-0001 is the clear choice.
The Woodbridge T-0001 sits at the intersection of genuine maximum flush performance and contemporary design that larger brands have been slow to offer. The skirted form factor carries a real cleaning advantage on the exterior, and the dual-flush system adds water-saving flexibility. The warranty trade-off is real but acceptable for most residential installations.
The Gerber Viper is a no-frills commercial-grade two-piece toilet that earns the maximum 1,000-gram MaP score through a large glazed trapway and a robust 3-inch flush valve, without the premium pricing of TOTO or Kohler equivalents.
Gerber built its reputation supplying toilets to builders and light commercial projects where durability and maintenance simplicity outrank design. The Viper reflects that philosophy: a straightforward two-piece siphonic toilet with heavy vitreous china construction, a fully glazed trapway, and a 3-inch flush valve that produces enough velocity to reach the MaP ceiling at 1.28 gallons. The Viper carries WaterSense certification and qualifies for utility rebates in the same programs as premium-tier alternatives.
Aggregated owner and contractor reviews describe the Viper as exactly what it claims to be: reliable, functional, and unpretentious. The most common positive theme is that it keeps working without requiring maintenance calls. The most common negative theme is that it offers nothing distinctive in appearance. For any installation where function matters more than aesthetics and volume pricing creates real cost differences, the Gerber Viper delivers the maximum MaP credential at the lowest cost on this list. Read more in our best Gerber toilets guide.
Gerber's contractor-grade positioning is genuine. The Viper is built to survive high-frequency use without requiring frequent parts replacement, and reaching the MaP 1000 ceiling at 1.28 GPF is the same performance benchmark as toilets that cost significantly more. For multi-unit housing, rental properties, and build-outs, it is the rational choice.
GPF (gallons per flush) measures how much water a toilet uses per flush, while MaP score measures how much solid waste the toilet can clear in a single flush using that water. A toilet with a low GPF rating can still earn a high MaP score if its flush valve, trapway geometry, and bowl design convert that water into effective waste removal force. The two metrics are complementary, not interchangeable.
The confusion between MaP scores and GPF ratings is common because both numbers appear on toilet spec sheets, and lower is better for one while higher is better for the other. GPF affects water bills and utility rebate eligibility; EPA WaterSense certification requires 1.28 GPF or less. MaP score reflects actual clog resistance and clearing performance; 1,000 grams is the maximum. A toilet rated at 1.0 GPF is not automatically a strong flusher, and a toilet rated at 1.6 GPF is not automatically more powerful than one at 1.28 GPF. The MaP test eliminates guesswork by measuring actual performance directly.
When shopping for a toilet, check both numbers together. A toilet with 1.28 GPF and a 1,000-gram MaP score is the ideal pairing: it saves water at every flush while demonstrating the highest verified clearing performance the independent test awards. Any toilet that scores below 600 grams on the MaP test should be considered risky for households with known clogging history, regardless of its flush volume.
EPA WaterSense certification requires a toilet to use 1.28 gallons per flush or less, but it does not set a minimum MaP performance threshold. A toilet can earn WaterSense certification and still score poorly on MaP testing, which is why checking both certifications matters. The toilets on this list earned both credentials, meaning they use less than 1.28 GPF and also reached the maximum 1,000-gram MaP score.
The EPA WaterSense program was established to reduce residential water consumption. A toilet using 1.28 GPF instead of the older 1.6 GPF standard saves approximately 4,000 gallons per person per year. WaterSense-certified toilets also qualify for utility rebates in most water districts, which can offset the purchase cost. The program requires flush performance testing, but its performance threshold is lower than the MaP 1,000-gram ceiling. The intersection of WaterSense certification and maximum MaP score is where the strongest and most efficient toilets sit, and six of the eight toilets on this list occupy that intersection.
For large families or high-use bathrooms, the American Standard Champion 4 or TOTO Drake are the most appropriate MaP 1000 choices. The Champion 4's 4-inch flush valve delivers a higher-volume surge that handles bulk loads efficiently even under frequent cycling, while the Drake's parts availability and documented reliability record make it easier to maintain when the toilet sees daily heavy use from multiple occupants.
High-use bathrooms differ from typical residential settings in two ways: the frequency of flushes is higher, and the range of users (children, adults, guests) creates more varied demands on the toilet. A toilet used six or eight times daily cycles its fill valve, flush valve, and flapper far more than one used twice daily, which accelerates wear. The TOTO Drake's documented parts longevity and availability make it the most maintainable option for this use pattern. The American Standard Champion 4's 4-inch valve creates more clearing force per flush, which can help in homes with older drain lines that may have partial root intrusion or mineral buildup. For families with children specifically, see our guide to best toilets for large families.
The Maximum Performance flush test, conducted by Veritec Consulting and IAPMO Research and Testing, publishes updated results regularly as manufacturers submit new models or revised designs for testing. Results are publicly available at map-testing.com and are sorted by score, brand, and model. Consumers can verify any MaP score by searching the model number directly on the published database before purchasing.
Because the MaP database is publicly searchable, it is one of the few areas in toilet purchasing where independent third-party data is readily available rather than relying on manufacturer claims. When a manufacturer publishes a MaP score in marketing materials, that score should match the entry in the public MaP database. If there is a discrepancy, the database entry takes precedence as the independently verified result. All MaP scores referenced in this guide are drawn from published test results rather than manufacturer marketing materials.
MaP 1000 means the toilet cleared 1,000 grams of standardized solid waste media in a single flush during the Maximum Performance test, which is the highest score the protocol awards. It is the strongest independent flush-performance certification available for consumer toilets.
Yes. The MaP protocol does not test beyond 1,000 grams because no realistic single-use household load exceeds that amount. Once a toilet clears 1,000 grams, the test stops and records the maximum score. Toilets that might technically clear more are still recorded at 1,000.
Most plumbing professionals consider a MaP score of 600 grams or higher to be solid for residential use. A score of 800 grams is strong, and 1,000 grams is the maximum. Toilets scoring below 500 grams are more likely to clog under heavy use or in homes with partial drain blockages.
No. MaP score and water consumption are independent. Several toilets on this list reach the 1,000-gram MaP maximum at only 1.28 GPF, which is 20 percent less water than the older 1.6 GPF standard. A higher MaP score reflects better engineering, not higher water use.
Yes. The full publicly searchable MaP test database is available at map-testing.com. You can search by brand, model, or score to verify any toilet's independently tested performance before purchasing. This is the authoritative source and supersedes any marketing claims.
For most households, yes. The TOTO Drake combines the maximum 1,000-gram MaP score with 1.28 GPF consumption, EPA WaterSense certification, a 3-inch flush valve, and parts that are widely stocked. No single toilet matches it across all five criteria simultaneously at its price point.
Both earn 1,000-gram MaP scores, but through different approaches. The Champion 4 uses a 4-inch flush valve at 1.6 GPF for maximum surge force. The Drake uses a 3-inch valve at 1.28 GPF with a precisely engineered siphonic trap. The Drake is more water-efficient; the Champion 4 moves more water per flush.
They can, but it is rare under normal residential use. A 1,000-gram MaP score means the toilet cleared the heaviest load the independent test applies, which exceeds any realistic single-use household volume. Clogs in MaP 1000 toilets almost always result from flushing non-flushable items, not from the toilet's flush capacity.
Most MaP 1000 toilets use fully glazed trapways measuring 2-1/8 inches to 2-3/8 inches in diameter. The glazing is as important as the diameter: an unglazed trapway of the same size provides more surface resistance and collects deposits faster, increasing clog risk over time.
Only if they also flush at 1.28 GPF or less. A MaP 1000 score alone does not qualify a toilet for WaterSense certification or its associated utility rebates. Six of the eight toilets on this list carry both qualifications. The American Standard Champion 4 uses 1.6 GPF and does not qualify for WaterSense rebates despite its maximum MaP score.
Replacing a 3.5 GPF toilet with a 1.28 GPF MaP 1000 model saves approximately 2.22 gallons per flush. At an average of five flushes per person per day, that is over 4,000 gallons per person annually, or roughly 16,000 gallons per year for a four-person household.
Yes. The Kohler Cimarron earns the same maximum 1,000-gram MaP score at 1.28 GPF with WaterSense certification. Its AquaPiston canister mechanism provides 360-degree water entry, which produces thorough bowl coverage. It is the correct choice for Kohler-brand loyalty or for buyers who prefer Kohler's service infrastructure.
The original Drake uses the G-Max flushing system with conventional rim holes. The Drake II replaces that with the Double Cyclone system, which uses two propulsion nozzles to generate a rotating rinse pattern across the entire bowl. Both earn 1,000-gram MaP scores; the Drake II adds better bowl coverage and Sanagloss glaze.
The skirted exterior itself does not affect internal components, but it does conceal the trapway, making access to the base more complex if the toilet needs to be set or reset. The fill valve and flush valve inside the tank are unchanged. Most repairs involving the tank internals are identical between skirted and non-skirted designs.
Yes, the Woodbridge T-0001 has published MaP test results showing the 1,000-gram maximum on its full 1.28 GPF flush mode. Buyers should confirm the specific configuration (model number and flush volume) matches the tested entry in the map-testing.com database when verifying this score independently.
Two-piece toilets like the TOTO Drake and American Standard Cadet 3 are generally easier to install than one-piece models because the tank and bowl ship and install separately, reducing weight at each step. One-piece models like the UltraMax II are heavier and may require two people to position safely over the flange.
Pressure-assisted toilets use compressed air to boost flush force and can produce very high MaP scores, but they are louder, more expensive to repair, and require more water pressure at the supply line to function. A gravity-fed MaP 1000 toilet delivers equivalent clearing performance more quietly and with simpler, cheaper repair parts.
The vitreous china bowl of any toilet, MaP rated or not, can last 50 years or more if undamaged. The mechanical components (fill valve, flush valve or flapper, trip lever) typically require replacement every 5 to 10 years depending on water quality and use frequency. A MaP 1000 rating reflects flush performance, not hardware longevity.
No. MaP score is determined by the complete toilet system: bowl geometry, flush valve size, trapway diameter and glaze, and jet configuration. Replacing the fill valve or flapper on an existing toilet will not change its MaP score. Achieving 1,000-gram performance requires a toilet that was designed and tested for it from the start.
The complete database of MaP-tested toilets is available publicly at map-testing.com, searchable by brand, model, MaP score, and GPF rating. Filtering results to show only 1,000-gram scores returns the full list of toilets that have reached the maximum rating, with the specific model numbers and flush volumes for each tested configuration.
The TOTO Drake is the best MaP 1000 toilet for most households: it earns the maximum independently verified flush score at 1.28 GPF, holds EPA WaterSense certification, and has the most accessible parts supply of any toilet on this list. For households that want the most powerful mechanical flush available and are not constrained by water efficiency goals, the American Standard Champion 4's 4-inch valve delivers the maximum MaP rating with a surge-style flush that nothing in the gravity-fed consumer market equals. For a skirted modern design or a one-piece form factor, the Woodbridge T-0001 and TOTO UltraMax II both bring the same maximum performance credential into more refined packages. The MaP 1000 rating is the highest standard in residential toilet performance, and every toilet on this list has earned it through independent testing rather than marketing claims.
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