What Is a MaP Flush Score? Everything You Need to Know

What Does MaP Stand For, and Who Runs the Tests?

Before MaP testing existed, shoppers had no reliable way to compare flush performance between brands. Marketing language like "powerful flush" or "clog-free guarantee" appeared on virtually every toilet box with no objective backing. The program changed that by creating a reproducible, apples-to-apples test that isolates flush effectiveness from every other variable.

Today, MaP testing data covers thousands of toilet models from virtually every major manufacturer sold in North America. When you look up a toilet on the MaP database, you can see exactly how many grams of simulated solid waste the bowl cleared during testing -- and whether it passed in one flush or required multiple attempts.

How Is the MaP Flush Test Performed?

The soybean paste medium was chosen after years of research because its density, viscosity, and consistency closely match real human waste. Latex casings prevent the medium from dissolving or breaking apart prematurely so that each test is reproducible. The same toilet model is tested multiple times; results must be consistent across runs for the score to be published.

A toilet must clear the entire quantity -- bowl, trapway, and the full drainline leading to the standpipe -- to receive credit at that increment. Any residue remaining in the bowl means the toilet does not receive a score at that level. This means MaP scores are genuinely conservative: a toilet that scores 600 g reliably removes 600 g every time under controlled conditions, not just on its best day.

The test also captures water use. A toilet is measured for its actual gallons-per-flush consumption, which is recorded alongside the flush score. This allows a direct comparison of efficiency versus performance -- some toilets achieve an 800 g score on 1.0 gallons per flush, while others need 1.6 gallons to reach the same level.

What Is a Good MaP Flush Score?

To put those numbers in perspective, researchers estimate average human solid waste per event falls between 150 and 350 grams depending on diet, age, and health. A toilet scoring 600 g has significant headroom above typical real-world demands. A toilet scoring 1,000 g -- the maximum possible -- is overengineered for residential use but may be appropriate for commercial restrooms, healthcare facilities, or households where plumbing issues are a recurring problem.

The sweet spot for most shoppers looking at the best flushing toilets available today is 600 to 800 grams. Toilets in this range deliver reliable single-flush clearing without the need for the oversized trapways and larger tanks that push a model toward 1,000 g territory.

How Does MaP Score Relate to GPF and EPA WaterSense?

The federal Energy Policy Act of 2005 capped new residential toilet water use at 1.6 GPF. EPA WaterSense, a voluntary labeling program launched in 2006, tightened that to 1.28 GPF and added a requirement that toilets pass MaP testing at a minimum of 350 grams. This is where MaP and WaterSense intersect formally.

However, 350 grams is a relatively low bar. Many WaterSense-certified toilets score well above that threshold -- the certification tells you the toilet uses no more than 1.28 GPF and meets a minimum performance floor, but it does not tell you whether the toilet scores 350 g or 950 g. You need to look up the MaP score separately for the full picture.

This is why savvy shoppers treat the two data points as a pair rather than substitutes. A toilet with WaterSense certification and a MaP score of 800+ grams at 1.28 GPF or less represents genuine efficiency without sacrificing flushing reliability.

Which Real Toilet Models Have the Highest MaP Scores?

Here is a breakdown of widely referenced models and their documented MaP performance across manufacturer published data and the MaP testing database:

It is worth noting that the American Standard Champion 4, while having a 1,000-gram MaP score, uses 1.6 GPF -- above the WaterSense ceiling. It is not the most water-efficient choice. If water savings matter to you alongside raw flushing power, the TOTO Drake II or UltraMax II offer 1,000 g at only 1.28 GPF, combining maximum performance with WaterSense efficiency.

For a curated selection covering these and newer models, see our roundup of best flushing toilets under 300 dollars and our comparison of TOTO vs. American Standard performance metrics.

Does a Higher MaP Score Always Mean Fewer Clogs?

MaP tests measure how much simulated waste can be evacuated from the bowl. What the test does not fully capture is how well waste moves through the trapway (the S-curve at the base of the toilet that provides the water seal) and into the drain. Trapway diameter and surface finish both matter here.

A fully glazed trapway has a smooth ceramic surface that reduces friction and allows waste to slide through with less resistance. An unglazed or partially glazed trapway has a rougher surface that can snag fibrous waste materials. Most manufacturers in the 800+ MaP score category do fully glaze their trapways, but it is worth confirming in the product specifications.

Trapway diameter also matters. Standard toilets have a trapway diameter of roughly 2 to 2.125 inches. The American Standard Champion 4 is notable for its 2.375-inch fully glazed trapway -- the widest in mainstream residential production -- which explains why it consistently receives strong owner reviews for clog resistance even in households that regularly use thick toilet paper. Learn more in our complete guide to trapway sizes.

Finally, the drain slope in your home affects how waste moves after it exits the toilet. The International Plumbing Code specifies a minimum slope of 1/4 inch per foot (about 2 percent) for drain lines. Older homes with improper slope or partial blockages from decades of mineral buildup may see more clogs regardless of toilet score. If clogs are a persistent problem in a home with an 800+ MaP toilet, the drain line is worth inspecting.

How to Look Up the MaP Score for Any Toilet

The MaP testing database is publicly accessible at map-testing.com. To look up a specific toilet, you can search by brand name, model name, or the toilet's manufacturing series number. Results are returned as downloadable PDF reports that include the MaP score, actual measured GPF, test date, and flush mechanism type.

A few practical notes when using the database:

• Search by exact model number when possible. Some brands use similar names across different product lines. The TOTO Drake and TOTO Drake II are distinct models with different flush systems and scores.
• Check the test date. Manufacturers occasionally revise flush valves or bowl geometry mid-production run. A MaP score from 2018 may not perfectly reflect a toilet purchased in 2026 -- though major changes are typically re-submitted for retesting.
• Look for the flush count column. Some database entries note whether the toilet cleared its maximum score in one flush or two. A single-flush clearance at 800 g is meaningfully better than a two-flush clearance at the same score.
• Cross-reference with WaterSense. The EPA WaterSense product search at epa.gov/watersense lets you verify certification status independently of manufacturer claims.

If a specific model does not appear in the MaP database, it either has not been submitted for testing or failed testing. Either outcome is a yellow flag when comparing alternatives that do have published scores.

MaP Testing for Dual-Flush Toilets: What You Need to Know

Dual-flush toilets present a specific challenge for MaP scoring because they have two distinct flush modes -- typically a low-volume liquid flush (0.8 to 1.0 GPF) and a higher-volume solid flush (1.28 to 1.6 GPF). MaP testing captures both, but the score most prominently reported is usually the full flush result.

When evaluating a dual-flush toilet like the TOTO Aquia IV, the full flush MaP score -- a perfect 1,000 grams on the 1.28 GPF cycle -- tells you how the toilet performs when handling solid waste. The liquid flush cycle (0.8 GPF on the Aquia IV) is designed only for liquid waste and is not expected to clear solids effectively; applying the MaP score to it would be misleading.

Dual-flush toilets are popular for their potential to save water -- households that use the reduced flush for appropriate waste can cut overall toilet water use by 20 to 30 percent compared to a single-flush 1.28 GPF model. However, owner reviews consistently show that many users default to the full flush out of uncertainty or habit, which reduces the actual water savings in practice. Read more in our dual-flush toilet pros and cons guide.