Find the Right Replacement Filters — Fast
FRF is a simple, helpful guide that points you to the correct filters for your home and car. Read the quick tips, then use the tool to jump straight to trusted retailers.
HVAC Filters
Browse sizes across Aerostar, Filtrete, Honeywell, Aprilaire, and more. Choose a size and MERV, then compare prices.
Browse HVACCar Filters
Pick your make, model, and year. We’ll help you locate cabin and oil filter options and check store availability.
Find Car FiltersAir Purifiers
Search your purifier model (e.g., “Levoit Core 300S”). See compatible replacement filters and jump to retailers.
Air Purifier FiltersFAQs
How do I measure HVAC filters?
Use the existing filter’s printed size (e.g., 16x20x1). If in doubt, measure the return grille opening and thickness.
What’s the right MERV for my home?
Many homes do well with MERV 8–13. If you choose higher, confirm your blower can maintain adequate airflow.
How often should I replace filters?
HVAC 1″: 1–3 months. Car cabin: 12–15k miles. Purifiers: typically every 6–12 months or per the manufacturer.