Follow these 3 easy steps:
Step 1 - Measuring Length and Width (L x W). (If your filter is not a square, the smallest measurement goes first).
Step 2 - Measure the thickness of your filter from front to back.
Step 3 - Put Your Measurements Together (L x W x D).
It’s as simple as that - You are now ready to buy the right filter for your AC or Furnace