MERV 8 Air Filter

A MERV 8 filter captures 70% or more of particles in the 3–10 micron range, which includes the most common household airborne contaminants. Dust mite debris, pollen, pet dander, mold spores, lint, textile fibers, and larger dust particles are all effectively captured at this rating. MERV 8 filtration also catches carpet fibers and cement dust in the 3–10 micron range, relevant in homes with recent construction or renovation activity.

What MERV 8 doesn't capture: fine particulates below 3 micron, including bacteria, smoke, and viruses. For households with those concerns, MERV 11 or MERV 13 provides meaningfully better capture. For most healthy households without severe allergy or respiratory concerns, a MERV 8 furnace filter delivers the right balance of particle capture and airflow without over-restricting the HVAC system.

Standard Sizes

The most common standard sizes for MERV 8 air filters are 16x20x1, 16x25x1, 20x20x1, 20x25x1, and 24x24x1. These fit many residential furnaces and air handlers with conventional 1-inch filter slots. All Filters stocks MERV 8 filters in all standard sizes with competitive pricing and free shipping on orders over $99.

Custom Sizes

If your system uses a non-standard filter slot, custom-cut MERV 8 filter media is available. Check the dimensions of your current filter. First look for a nominal size is printed on the cardboard frame and use those dimensions to search at All Filters. You may need to measure an old filter or even your filter cabinet. If your measurements round up to widely available nominal size, order that! If not, use your filter's measurements to the nearest 1/8" inch. Subtract 1/4" from slot or cabinet measurements to ensure fit. If you can't find an exact match, contact our customer service team, available seven days a week.

Checking Your Existing Filter

For many, the easiest way to confirm your filter size is to pull out the existing filter and read the nominal dimensions printed on the frame. For example, "20x25x1" or "16x20x1." Note the depth (the third number): most residential systems use 1-inch filters, but some cabinets take 2" or even whole-house style 3–6" media. Make sure your replacement matches all three dimensions.

All Filters offers MERV 8 air filters in a wide range of standard and custom sizes, including SpiroPure house-brand options priced to save without sacrificing performance. Most multi-packs and all orders over $99 ship free nationwide, and our customer service team is available seven days a week to help confirm sizing or compatibility. Set up an email replacement reminder so your next filter change happens on schedule. Shop our full selection of furnace air filters to find your size.