How to Cut a Trim-to-Fit Filter

What is a Trim-to-Fit Filter?

A trim-to-fit filter (or cut-to-fit filter) is exactly that: a filter you can cut to match the size of the filter slot on your furnace or window air conditioning unit. Since these filter slot sizes can vary greatly among furnace and air conditioning manufacturers, a trim-to-fit filter is sometimes the best way to go, especially if the opening for your filter is oddly-shaped.

How to Cut a Cut-to-Fit Filter | Cutting a Trim-to-Fit Filter

Cutting a trim-to-fit filter is easy. Simply grab your scissors or utility knife and cut the filter using as straight a line as you can manage. Cutting it along a ruler is recommended to ensure that you’re cutting it as straight as you can. Don’t worry; you won’t harm the functionality of the filter by using scissors or a knife.

How Do I Know What Size Filter I Need?

When purchasing a trim-to-fit filter, make sure you buy a larger size than you need. We stock up to size 20" X 25" X 1." If you’re not sure what size filter you need, pull your current filter out of the side of your furnace or air conditioning unit and look at the size listed on it. If there isn’t a filter in your unit, feel free to call us for help with the measurements, or refer to your owner’s manual. You may also be able to find what size filter you need on the manufacturer’s website, or the sizes might even be listed directly on your unit.

How Often Do I Change My Furnace Filter? (Or A/C Filter)

The answer to these questions will depend on the exact filter you purchase — not all filters are built the same. Some filters are made out of pleated paper products, while others are made of higher quality materials. Pleated paper filters typically need to be changed every 30 days, or every couple of months.

Since our filters are made of higher quality materials, though, they will need to be changed at least every 90 days. There are some circumstances where you might not need to change it as often. For instance, if you live in a rural area and your home environment isn’t subject to as many airborne allergens and pollutants, you may not need to change it every 90 days.

Can I Fold My Furnace Filter to Make it Fit?

Yes, you can fold your furnace filter. Folding a furnace or an air conditioning filter to make it fit will not negatively impact its performance. The particles and pollutants will still be trapped by the filter.

Who Can I Call If I Have Questions?

Feel free to call us at 1-800-444-2072 if you have any questions about trim-to-fit filters, filter sizes, or about anything else. We are incredibly knowledgeable about anything and everything there is to know about home filters; we have been in the residential filter business for over 30 years, after all! We’re available during regular business hours, Monday through Friday. We look forward to hearing from you!