What is the MaP Toilet Rating?

As I said in my last post, some toilets are high efficient (use little water) but are low performance. There is a way to determine if a high efficient toilet will flush well before it is installed.  It is called the MaP rating.  MaP stands for Maximum Performance.Open Door Toilette

MaP is a Maximum Performance scale that rates toilet efficiency and flush performance, plus gives detailed information on individual toilet characteristics. The result is up-to-date, independently verified comprehensive toilet information in a SEARCHABLE database.

IMPORTANT:  MaP scores represent the number of grams of solid waste (soybean paste and toilet paper) that a particular toilet can flush and remove completely from the fixture in a SINGLE FLUSH.

History of MaP Toilet Testing

MaP was developed in 2002-03 in response to the many complaints of the 1990s about the new “low-flow” toilets (which, by the way, flushed with 1.6 gallons of water, less than 50% of the water used in its predecessors of the 1980s!).  MaP development was sponsored by members of the municipal water utility industry.  For more information on the background of MaP over the past two decades, click here.

While many toilet performance tests have existed for years (manufacturers tests, Consumer Reports and plumbing codes), ONLY MaP offers consumers the test results from closely replicating REAL WORLD demands put upon a toilet.  MaP testing was initiated specifically to identify how well popular models performed using realistic test media (fecal simulation).

Testing Procedures

“MaP incorporates the use of soybean paste and toilet paper to duplicate the real world demands put upon toilets.  Each toilet is tested to failure – – that is, soybean paste is repeatedly added to the toilet until the fixture can no longer remove it in a single flush.  Since 2003, over 3,500 different tank-type toilet models have been tested and reported in the MaP online database.  Today, 3,360 tank-type toilet models are listed in the MaP’searchable’ database.” – MaP Testing, http://www.map-testing.com/

The above is taken directly from the MaP website.  I couldn’t say it any better, so I quoted it.

The MaP scale ranges from 250 – 1,000.  It is the number of grams of waste a toilet will flush cleanly.  At Apple Plumbing will only install toilets with a MaP rating of 800 or better. Click the image below to see what the different ratings mean.


We had one customer who purchased a very nice looking Kohler toilet.  We did not check the MaP rating prior to installation.  Turns out is had a MaP rating of 250 and did not flush solid waste at all!

I’ve see some toilets at the big box stores with a rating on the box of 1,250.  Beware, this would not be a MaP rating but a rating determined by the manufacturer or a testing agency no recognized by MaP or the EPA.  The maximum MaP rating is 1,000.  As I said, we only install toilets with a MaP rating of 800 or more.  We have found that those toilets flush very well with little or no problems to the consumer.  However, if you try hard enough, you can clog any toilet.  Also, beware of ads showing toilets flushing golf balls, balloons, etc.  You don’t flush these items during daily use of your toilet so the ads are meaningless.

Only judge a toilet by its MaP rating!

Maryland Breakthrough Business Award
Carroll's Best

Sign Up for Our Email List