How to Measure Your AC Filters Properly (and Get New Filters Delivered Right to Your Door!)

Keeping your AC filters clean and up-to-date is one of the simplest ways to maintain your HVAC system’s efficiency, reduce energy costs, and improve indoor air quality. But when it comes to buying new filters, figuring out the right size can be tricky if you’re unsure how to measure them. Here’s a step-by-step guide to help you measure your filters like a pro!

Step 1: Remove Your Current Filter

Turn off your HVAC system, locate your air filter (usually in a return air vent or at the HVAC system itself), and carefully slide it out.

Step 2: Check for a Label

Most filters have their dimensions printed on the frame. It’s often a three-number format like 16x25x1. This represents the length, width, and thickness (all in inches). If your filter already has the size printed, use these dimensions for purchasing a replacement.

Step 3: Measure Manually If Needed

–For a Traditional Filter
If there’s no visible size, measure it yourself using a tape measure. Start with the length and width; round up to the nearest inch for simplicity since filters are typically sold in standard sizes.

1. Length: Measure the longer side of the filter.
2. Width: Measure the shorter side.
3. Thickness: Measure the depth of the filter. Most common depths are 1 inch, but some HVAC systems may require 2-inch or even 4-inch thick filters.

If you currently use a custom-cut mesh filter, measuring for a replacement can be a bit different, as these filters may not adhere to standard sizes. Here’s a detailed guide to measuring your custom mesh filter properly:

–For Custom-Cut Mesh Filter:
If you currently use a custom-cut mesh filter, measuring for a replacement can be a bit different, as these filters may not adhere to standard sizes.

1. Gather the Right Tools: Use a flexible measuring tape or ruler that can easily measure smaller units to get precise measurements.
2. Measure Length and Width: Lay your mesh filter on a flat surface. Measure the length (the longer side) and width (the shorter side) of the filter frame. Custom filters often require exact measurements, so measure to the nearest 1/16 of an inch if possible.
   • Tip: Custom filters sometimes warp slightly over time, so measure both sides of each dimension (top/bottom and left/right) to ensure accuracy. Use the larger measurement if there’s a slight difference.
3. Measure Thickness/Depth: Custom mesh filters might vary in thickness, especially if they’ve been modified or altered over time. Measure the depth of the filter carefully, as even small thickness changes can impact performance. The depth is typically anywhere from 1/2 inch to 2 inches, so verify to get the right replacement.
4. Note Material and Specifications: Custom mesh filters can have different material types, densities, and mesh patterns. Record any additional specs, such as material (e.g., aluminum, fiberglass, or electrostatic).

Step 4: Double-Check Your Measurements

It’s essential to double-check your measurements because even a slight difference can affect your filter’s fit and functionality. Most filter sizes are slightly smaller than listed (e.g., a filter listed as 16x25x1 might measure 15.5×24.5×0.75). This allows for easy insertion and removal.

Step 5: Order the Correct Filter Online

Now that you know your filter size, you’re ready to order a new one! The best part? We now offer an online filter store to make replacing filters a breeze. You can select the right size and type of filter, order with just a few clicks, and have it delivered directly to your door—quickly and at a competitive price.