Tricks of the Trade

Guide to MaP toilet testing & flush ratings for low flow toilets


With an increasing public concern for the environment and strict regional legislation regarding water consumption, low flow toilets have become the modern standard in the plumbing industry. The first low flow toilets were introduced to the market decades ago in response to regional environmental regulations. Early low flow toilet models operated with 1.6 gallons per flush, or gpf. Today’s toilet manufacturers now offer models that use up to half as much water and perform with significantly better reliability. By selecting toilets that are tested according to MaP, or Maximum Performance, trade professionals have added assurance that they’re providing their customers with the most rigorously tested toilets on the market. Use this guide to MaP toilet testing to see how you can help your customers find the right low flow toilets for their needs.

  • MaP is the industry standard for toilet testing in the United States. By developing a toilet testing system based on quantifiable data, MaP testing sets the bar for toilet performance. MaP uses realistic organic-based test media to accurately simulate authentic toilet demands. Toilet performance test media is measured in grams, and manufacturers voluntarily submit their toilets to be tested to earn the MaP certification. MaP is the only third-party testing method that certifies toilet performance of up to 1000 grams of waste removal.

  • MaP tests toilets for efficiency and performance. If you have customers who are worried about low flow toilets clogging, you can help to reduce their concerns by explaining to them that MaP tests toilets for both efficiency and performance.

    • Toilet efficiency: This refers to the amount of water that a toilet uses in each flush. The Environmental Protection Agency’s, or EPA’s, WaterSense® program requires toilets to have a flush rating of 1.28 gpf or less in order to earn the WaterSense® label. MaP certifies some toilets for efficiency that operate with as little as 0.8 gpf.

    • Toilet performance: This refers to how reliably a toilet operates in terms of the capacity of waste that it is able to flush. As mentioned above, MaP certifies performance by testing up to 1000 grams of waste. This is almost three times the WaterSense® requirement of 350 grams, which itself is over twice the average demand for homeowners, which is about 150 grams of waste per use.

  • MaP PREMIUM toilets offer superior efficiency and performance. MaP goes beyond simply giving toilets a pass or fail rating for efficiency and performance. Toilets that are certified to perform significantly better than other toilets on the market are given the MaP PREMIUM rating. In order to earn the MaP PREMIUM rating, a toilet must operate with no more than 1.1 gpf and remove at least 600 grams of waste in a single flush.

    Pro tip: While all MaP PREMIUM toilets operate with up to 1.1 gpf, there are select MaP PREMIUM toilets available on the market that are certified at 0.8 gpf while still removing at least 600 grams of waste. This is an advantage for trade professionals because they’re able to offer toilets to their customers that yield maximum water savings without sacrificing performance. Shop 0.8 gpf MaP PREMIUM toilets >>

  • MaP PREMIUM toilets may help earn rebates, tax credits and more. In addition to reducing water use, MaP PREMIUM toilets offer consumers additional ways to save. Many MaP certified toilets and all MaP PREMIUM toilets are also WaterSense certified. With the WaterSense label, these toilets may qualify consumers for government rebates and tax credits in certain areas. Use the EPA’s rebate finder to help your customers find out if rebates are offered on WaterSense products in your area.

    Pro tip: For customers who are pursuing a LEED certification, toilets with a MaP PREMIUM rating can help. That’s because MaP PREMIUM toilets that are WaterSense labeled may contribute to points towards earning a LEED certification. Discover the benefits of becoming a LEED-accredited contractor >>

As the largest wholesale plumbing supplier in North America, Ferguson is your go-to source for toilets and toilet parts. From one-piece and two-piece toilets to elongated and round bowls, we have the right toilets you need for every project. Buy toilets online or find your local Ferguson to get expert support for your pro trade business.