Create Custom Size HVAC, Air or Furnace Filters

Build your custom air filter for home, commercial or office in four easy steps!

How to measure your filter
StepEnter your filter dimensions (actual) x x
StepSelect your performance rating

Additional Info

Nominal Depth 1”
Actual Depth 3/4”
Nominal Depth 2”
Actual Depth 1 3/4”
Minimum Size
5” x 5”
Maximum Size
40” x 40”

Please Note: Due material limitations used to build a custom filter, we construct a double filter (two filters fused together) when any filter dimension is larger than 24.75” on both sides and or larger than 29.75” on one side. Please allow up to an additional five (5) business days for processing your custom filter order.

Custom filters are not eligible for return or refund.

How to Measure Your Filter

Steps 1 & 2

Measuring Length and Width (L x W). (If your filter is not a square, the smallest measurement goes first).

Step 3

Measure the thickness (Depth) of your filter from front to back.

Step 4

Put Your measurements together (L x W x D).

Actual Size

A filter’s true dimensions.

Example: 19.75” x 19.75” x 1”

Nominal Size

Rounded numbers used by manufacturers.

Example 20” x 20” x 1”

View Detailed Instructions

What’s the difference between actual and nominal size?

Actual Size

A filter’s true dimensions.

Example: 19.75” x 19.75” x 1”

Nominal Size

Rounded numbers used by manufacturers.

Example 20” x 20” x 1”

Learn More