What is the difference between MERV, MPR, and FPR ratings on air filters?

Sometimes manufacturers or sellers of air filters will create their own rating systems as a marketing strategy to make it seem like their filters are different or somehow better than other filters on the market. In general, we recommend that you use the universal industry standard MERV rating (Minimum Efficiency Rating Value) to determine filter efficiency. Every air filter in the US has a MERV rating, as it is the only nationally regulated system for testing air filter efficiency. The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) created the MERV rating system to measure an air filter’s ability to capture air particles and pollutants. MERV ratings go from 1-20, with 1 filtering the least amount of particles and 20 filtering the most. In general, MERV 8, MERV 11, and MERV 13 filters are the most commonly offered and used ratings as they allow for adequate filtration without impeding the airflow of HVAC systems.

In the case of MPR rating (Microparticle Performance Rating), this is a rating system created by 3M Filtrete. MPR measures a filter's ability to capture particles smaller than 1 micron in size. The measurements go from a basic 300 MPR to a premium 2800 filter rating. The direct comparisons for MERV ratings and MPR ratings are as follows:

  • MPR rating 300 - 600 - MERV 8
  • MPR rating 900 - 1,000 - MERV 10
  • MPR rating 1,000 - 2,000 - MERV 11
  • MPR rating 1,500 -1,900 - MERV 13

Another commonly found rating that was created by Home Depot to measure the air filters offered in their stores is the FPR rating (Filter Performance Rating). It uses a number scale of 4 - 10 to rank filters, and further differentiates each with a color-coded system. FPR 4 rated filters are considered a “Good” rating, while FPR 10 constitutes a “Premium” filter. The direct comparison for MERV ratings and FPR ratings are as follows:

  • FPR rating 5 - MERV 8
  • FPR rating 6 - MERV 10
  • FPR rating 7 - MERV 11
  • FPR rating 10 - MERV 13