What does this tool do?
Air filters are replaced on a fixed interval, so annual demand is the number of changes divided by the pack size. This calculator uses common nominal sizes and shows both the replacement count and the yearly spend.
The Formula
Changes per year = 12 ÷ replacement interval (months); annual cost = (changes ÷ pack size) × pack priceFrequently Asked Questions
How often should I change the filter?
Every 60 to 90 days is typical for a standard 1-inch filter. Homes with pets, allergies or heavy dust may need changes every 30 to 45 days.
Does a higher MERV rating cost more to run?
Very high ratings can restrict airflow if the system was not designed for them. Match the rating to the equipment and check for weak airflow after changing.