FPR vs MERV vs MPR Rating: What Is the Difference?

When considering FPR vs. MERV vs. MPR, you should know that the one thing they all have in common is that all are different rating systems for HVAC air filters. However, of the three, MERV is the only one considered the industry standard. The others are proprietary names.

In other words, popular brands are using their own rating systems to rate their filters. As you might expect, where products with proprietary rating systems compete with those using the industry’s standard rating system, there’s bound to be confusion.

So, the plot thickens. This goal of this article is to sort out the proprietary vs. non-proprietary confusion. Read this carefully if you want to avoid some frustration the next time you shop for a home HVAC filter!

What Are HVAC Filters?

You might ask this question if you’ve never maintained a furnace or HVAC (heating-ventilation-air conditioning) system before. This is the case for a lot of people.

Quite simply, as air comes into your HVAC system from outdoors and is heated or cooled, a variety of organic and inorganic particles need to be removed before it’s completely safe and healthy to breathe. That’s the job of HVAC filters.

Since HVAC components themselves are also proprietary, each brand or model needs a specific filter. Because these filters vary in size, each specific filter only fits a limited category of HVAC systems—maybe even just one

That’s why people often need help selecting the right filter at the store. Moreover, each type of filter is further distinguished by its rating—as we’ll discuss next.

The FPR vs. MERV vs. MPR Rating Scales

Filter-rating scales indicate not only the quality or the air filtration but also the specific types of particles removed. All filters sold must meet basic safety expectations, and most brands have higher-level filters to address particular needs and situations.


MERV stands for Minimum Efficiency Reporting Value. As mentioned above, the MERV rating system for HVAC filters is the industry standard. Thus, it’s clear, uniform, and considered trustworthy.

MERV ratings report a filter’s ability to remove air particles between 0.3 and 10 microns (µm). The MERV rating scale indicates the efficiency of a filter at doing this.

The MERV scale begins at level 1 (3.0 to 10.0 µm or less than 20% of particles). It goes up to level 16 (0.3 – 1.0 µm or over 75% of particles). Typical MERV ratings for furnace filters are 4, 8, 11, or 13—with various pollutants removed at each level of filtration.

For example, a MERV 4 filter removes dust, lint, and pollen. However, a MERV 13 filter removes those, as well as dust mites, mold, pet dander, smoke, smog, viruses, bacteria, and more.

Did you know that a filter with a very high MERV rating removes particles so fine that the airflow resistance in the filter can sometimes damage HVAC units using it? Be sure that your system can handle this level of filtration before buying the filter!

To summarize, the MERV levels indicate precisely what a buyer is paying for when shopping for home filters and can make informed decisions about whether any given filter will meet (or exceed) their household’s needs.


FPR (which stands for Filter Performance Rating) is a rating system developed by and is exclusive to Home Depot, the giant home repair, maintenance, and furnishing retailer.

While FPR ratings correspond to MERV, it’s a rough set of comparisons. For example, a MERV 6 rating has no equivalent FPR. There also is no exact FPR equivalent to a MERV 13 rating.

Consumers might find it challenging to interpret these discrepancies when shopping for Home Depot furnace filters if they’re more familiar with brands that use MERV or another rating system, such as MPR


MPR is a filter-rating system developed by the 3M corporation for its line of Filtrete filters. Filtrete is a well-known brand that’s sold by Amazon, Target, Walmart, and other large retailers, among others.

Having just read about the FPR ratings, you won’t be surprised to learn that there are discrepancies between the MPR and MERV ratings, as well as between the MPR and APR ratings (APR is a rating used by the brand Accumulair).

Plus, sales of Filtrete filters aren’t limited to a single retailer, either, as is the case with APR filters. This means that many retailers, including independent ones, must expect their customers to navigate two different rating systems: MERV and MPR.

The Proprietary Rating Issue Broadly

The filter industry is hardly the only one impacted by proprietary rating systems that exist alongside those developed as industry standards. The situation affects everything from capital markets to environmental sustainability, not to mention everyday consumer products.

According to CENELEC, a European organization that supports the development of industry standards, “standards are everywhere and play an important role in the economy.” Standards achieve the following:

  • Make it easier for different businesses to collaborate.
  • Make it possible for companies to adhere to relevant laws and regulations.
  • Hasten the introduction of new and innovative products.
  • Make it possible for new and existing products, services, and processes to be interoperable with those that already exist.

Still, as long as there’s healthy competition in the marketplace, conflicting standards probably will continue to occur. It is important to note that most filter manufactures who utilize a proprietary rating system, such as FPR or MPR, will also provide the closest equivalent MERV ratings in the product details. Find and use the MERV rating to more easily compare filter options.

Filtering out the Best Information

Confusing as the different filter-rating systems may be, HVAC filters are nonetheless critical to your home and the health and safety of those living there. This has never been more important than now, with increased air pollution.

We can expect the issue of FPR vs. MERV vs. MPR to continue and hope that employees of the various companies selling air filters can assist customers adequately in making an informed decision before buying.

At Discount Filters, we believe in being upfront with our customers about what our products do without throwing other confusing ratings into this mix. This is why we only utilize industry-standard MERV ratings for our filters. If you’re interested in what our filters can do for you and your home, check them out here!

5 thoughts on “FPR vs MERV vs MPR Rating: What Is the Difference?”

  1. What is MERV rating of hogs hair filter? How frequently should hogs hair be replaced?
    Which filter is
    Most effective??

    • Hey Ruth! It’s hard to say without seeing the filter, but we found a listing that stated that the Flanders Hog Hair Air Filter Roll had a MERV 5 rating. Hope this helps!

  2. I bought an fpr 8 air filter, 20x25x4 at home depot, is that OK and how does it compare to a MERV. I dont use the air filter continuously, only occasionally.

    • Hi Greg! Great question. Unfortunately, there is no exact FPR equivalent to a MERV rating. However, an FPR 8 filter very roughly compares to a MERV 11 or 13. We hope this helps!

  3. My vet said to get the very best filter I can due to my cat’s allergies; she suggested a MERV 13 rating. I have a Trane xr12. I saw your statement “Did you know that a filter with a very high MERV rating removes particles so fine that the airflow resistance in the filter can sometimes damage HVAC units using it?” So I called Trane, they said I had to call the authorized dealer in my area. I did, but the dealer didn’t know if a MERV 13 would hurt my unit or not. Can you tell me what is the highest MERV rating my unit can use? If not, can you tell me who can? Thx!

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