MaP Score 500 vs 800 vs 1000: What the Numbers Mean

What Is a MaP Score?

What does a MaP score of 500 actually mean in real use?

How do MaP scores of 500, 800, and 1000 compare side by side?

Which real toilet models score 1000g on the MaP test?

Does a higher MaP score always mean better clog resistance?

MaP Score and EPA WaterSense: How They Work Together

MaP testing and EPA WaterSense certification are separate programs that complement each other. EPA WaterSense is an efficiency label: it certifies that a toilet uses 1.28 GPF or less AND passes a minimum 350g MaP flush test. WaterSense does not distinguish between a 350g toilet and a 1000g toilet -- both receive the same blue label if they meet the GPF cutoff.

This is why checking the MaP database directly matters. A toilet can carry the WaterSense logo and still only score 350g, which is the bare minimum. When you search map-testing.com by brand and model, you see the actual gram score rather than just the pass/fail used for WaterSense certification. Pairing a WaterSense-certified model with a 1000g MaP score gives you both water savings and genuine flushing power -- the combination most plumbers and home inspectors recommend.

For a broader look at how these factors play into choosing a high-performing toilet, see our guide to the best flushing toilets across all price tiers.

Expert Take

WaterSense saves you money on water bills and often qualifies for utility rebates. MaP score tells you whether the toilet will actually do its job without a plunger. Both matter. If you have to choose, prioritize the MaP score first -- a low-GPF toilet that clogs constantly costs more in plumber calls than it saves in water.

How MaP Testing Actually Works: The Lab Process

The MaP flush test follows a rigorous protocol. Testers load a measured quantity of soybean paste media into the bowl -- the paste has been calibrated to match the specific gravity and consistency of real solid human waste. They flush the toilet once, then examine whether the bowl cleared completely. If it clears, they increase the media weight and repeat the process until the toilet fails to clear the bowl in a single flush. The highest weight it successfully clears is the MaP score.

Each model is typically tested three times at each weight increment. Testers also measure water consumption per flush using calibrated flow meters to confirm GPF claims. Results are submitted to a central database maintained by Veritec Consulting and published without modification. Manufacturers cannot cherry-pick test runs or submit only favorable results -- the published score is the test score.

This independence is what makes MaP scores trusted by plumbing contractors, home inspectors, building engineers, and renovation buyers in ways that manufacturer marketing copy simply is not. When a plumber recommends a toilet, they typically reference the MaP score, not the brand's advertising description of "PowerFlush" or "TurboJet" technology.

Trapway Size and Its Relationship to MaP Score

The trapway is the curved internal channel through which waste exits the toilet bowl into the drain line. Its diameter directly constrains maximum flushing capacity. A 2-inch trapway represents the older minimum standard and typically caps MaP performance in the 300g to 500g range. A fully glazed 2-1/8 inch trapway is common in mid-tier 800g models. The 2-3/8 inch fully glazed trapway -- found in the American Standard Champion 4 and several TOTO models -- is closely associated with consistent 1000g MaP ratings.

"Fully glazed" means the ceramic coating that makes the bowl surface slick and easy to clean extends all the way through the trapway channel, not just the visible bowl interior. An unglazed or partially glazed trapway creates friction and accumulation points that restrict flow and cause waste to stick, reducing effective flushing power even when water volume is adequate.

For households dealing with frequent clogging, checking both the MaP score and the trapway diameter and glaze specification is the most reliable diagnostic step before buying a replacement toilet. These two data points appear in every manufacturer's specification sheet and explain the vast majority of performance differences between models at the same price point.

Related: Toilet Trapway Size Guide: 2-Inch vs 2-3/8 Inch and Best Clog-Resistant Toilets: What Actually Prevents Clogs.

Brand-by-Brand MaP Performance Overview

TOTO

TOTO is the most frequently cited brand for high MaP scores across its product line. The Drake (two-piece, 1.6 GPF) was among the first mass-market toilets to receive a 1000g MaP rating, and the updated Drake II (1.28 GPF) maintained that score at 20% lower water use. The UltraMax II one-piece carries a 1000g rating at 1.28 GPF. The Aquia IV dual-flush hits 1000g on its 1.0 GPF full-flush mode. TOTO's Double Cyclone and Tornado Flush rim-jet designs are specifically engineered to generate high bowl-rim water velocity, which translates directly to MaP performance by using water flow energy rather than volume.

American Standard

The Champion 4 is American Standard's flagship for flushing power, with a documented 1000g MaP score and a 2-3/8 inch fully glazed trapway that is the widest in its mainstream product tier. The Cadet 3 scores between 600g and 800g depending on the specific configuration. The VorMax series, with its single side-jet flush design rather than a traditional rim, achieves 1000g while also improving bowl coverage and cleaning. The H2Option dual-flush model maintains competitive MaP scores (800g to 1000g on full flush) while offering a 0.92 GPF option for liquid-only flushes.

Kohler

Kohler's Highline line spans a wide MaP range depending on model year and flush valve configuration. Older Highline models can score as low as 400g to 500g. The Cimarron with Class Five flushing technology reaches the maximum 1000g score. The Kohler Santa Rosa one-piece scores lower, in the 800g range. Kohler's AquaPiston canister valve, used across the Cimarron, Wellworth, and other lines, eliminates the flapper in favor of a 360-degree water entry valve that improves flush speed and MaP performance versus older flapper designs.

Woodbridge

Woodbridge entered the US market with the T-0001 one-piece dual-flush model, which independently tested to 1000g despite its lower price point. The brand's straightforward design -- skirted trapway, soft-close seat, dual-flush 1.0/1.6 GPF -- has made it a popular recommendation in the value tier. Owner reviews on major retail platforms consistently cite performance meeting or exceeding expectations, which aligns with its published MaP data.

Swiss Madison

Swiss Madison's Chateau and Sublime models have appeared in MaP testing with scores in the 800g to 1000g range for their full-flush setting on dual-flush configurations. The brand targets the design-conscious buyer who wants a rimless or skirted-trapway aesthetic and relies on MaP data to back up performance claims rather than marketing copy. Check the specific SKU on map-testing.com before purchasing, as MaP scores can vary between color variants and flush-valve configurations within a model family.

Gerber

Gerber's Viper and Avalanche models were engineered specifically to achieve 1000g MaP ratings. Both use a 2-3/8 inch fully glazed trapway and a high-speed flush valve. Gerber is less frequently stocked in big-box retail than TOTO or Kohler but is widely available through plumbing supply houses, making it a common professional recommendation for replacement installs and new construction where the buyer is working with a plumber rather than shopping a home improvement store aisle.

What MaP Score Should You Target?

The right target depends on household size, usage patterns, and existing plumbing conditions:

• 1-2 person household, modern plumbing, no history of clogs: 500g to 800g is sufficient and gives you flexibility to choose a design or price point you prefer.
• 3-5 person household: 800g minimum. Aim for 1000g if your budget allows, because the price premium between an 800g and 1000g toilet at the same brand tier is often less than $50.
• Older home with slower drain lines or shorter drain-line slope: 1000g is strongly recommended. Poor drain-line conditions magnify any flushing weakness.
• Household with children or a history of chronic clogging: 1000g with a fully glazed 2-3/8 inch trapway. American Standard Champion 4, TOTO Drake II, or Gerber Viper are the three most cited professional recommendations for this scenario.
• Commercial or high-traffic restroom: 1000g is the standard. Anything below creates maintenance liability.

Also consider reading our guide to toilets designed for heavy use if your household has above-average demand, and our dual-flush toilet review if water savings alongside high MaP scores is a priority.

Common Misconceptions About MaP Scores

Misconception 1: Higher GPF always means higher MaP score

This is the most widespread misunderstanding about toilet performance. GPF measures water volume consumed per flush; MaP measures flushing effectiveness. The two are related but not linearly correlated. A 1.6 GPF toilet might score only 500g if its trapway is narrow and unglazed. A 1.28 GPF toilet with a superior trapway and rim-jet design can score 1000g. The shift to 1.28 GPF WaterSense standards forced manufacturers to engineer more efficient hydraulics, and many modern 1.28 GPF models outperform older 1.6 GPF designs on MaP by a significant margin.

Misconception 2: Dual-flush toilets sacrifice MaP performance

Dual-flush toilets use two flush volumes: a lower GPF for liquid waste and a full flush for solid waste. The MaP score for a dual-flush toilet is measured on the full-flush setting only. Many dual-flush models -- including the TOTO Aquia IV and American Standard H2Option -- achieve 1000g on their full flush while still offering a 0.8 to 0.92 GPF option for lighter loads. The dual-flush mechanism itself does not inherently reduce solid-waste flushing performance.

Misconception 3: MaP score only matters for large households

Even a single-person household benefits from a higher MaP score because flushing performance degrades over time as mineral deposits accumulate inside the trapway, and as flush valves wear and deliver less water per flush. A toilet that started at 600g may effectively perform at 400g after five years of normal use. Starting with a 1000g score gives you a performance buffer that keeps the toilet reliable throughout its service life without requiring maintenance or rebuild kits.