Furnace filters, scored
These are the furnace filters we rate highest, best score first. What you actually want to compare is how fine a filter traps particles - its true MERV (the one industry standard, ANSI/ASHRAE 52.2). The big sticker numbers, 3M's MPR and Home Depot's FPR, are scales those sellers made up, and they don't map cleanly to MERV - so we show you the real MERV. The "$/yr" figure is what you'll spend on this filter in a year, from its price and how often the maker says to swap it, for a 20x25 filter - the size we price every entry at, since the same filter can cost two or three times as much in another size.
| Score | Filter | True MERV | Depth | $/yr |
|---|---|---|---|---|
| 6.0 | Aprilaire 213 (4-inch media, MERV 13) | MERV 13 | 4" | $65 |
| 6.0 | Aprilaire 413 (4-inch media, MERV 13) | MERV 13 | 4" | $65 |
| 6.0 | Honeywell FC100A1037 (4-inch media, MERV 11) | MERV 11 | 4" | $39 |
| 6.0 | Lennox Healthy Climate X6673 (5-inch media, MERV 11) | MERV 11 | 5" | $39 |
| 5.9 | Nordic Pure MERV 12 (1-inch) | MERV 12 | 1" | $39 |
| 5.9 | Amazon Basics MERV 11 (1-inch) | MERV 11 | 1" | $30 |
| 5.2 | Aerostar MERV 13 (1-inch) | MERV 13 | 1" | $55 |
| 3.9 | 3M Filtrete MPR 1500 (Allergen) | MERV 12 (MPR 1500) | 1" | $74 |
| 3.7 | Flanders EZ-Flow II Fiberglass (throwaway) | MERV 1 | 1" | $73 |
| 3.3 | 3M Filtrete MPR 1900 (Premium Allergen) | MERV 13 (MPR 1900) | 1" | $92 |
| 3.3 | Honeywell Home Elite Allergen FPR 10 (1-inch) | MERV 13 (FPR 10) | 1" | $108 |
If you're wondering why a familiar name scores lower than you expected: when a brand buries its true MERV behind an MPR or FPR number, we cap its honesty score, and a high-MERV filter crammed into a thin 1-inch panel gets flagged because it can choke your airflow. The full reasoning is in the methodology.
FAQ
- How are these furnace filters ranked?
- Best score first. Every score is our opinion under the published furnace-filter rubric, computed from the filter's true MERV (ANSI/ASHRAE 52.2), how plainly that rating is disclosed, airflow fit, and its real annual cost. The full score-event breakdown is on each scorecard.
- What is the difference between MERV, MPR, and FPR?
- MERV (ANSI/ASHRAE 52.2) is the one industry standard for how finely a filter traps particles. MPR is 3M's own scale and FPR is Home Depot's, and neither maps cleanly to MERV - so we always show the true MERV alongside any proprietary number.
- What does the $/yr column mean?
- It is what you will spend on this filter in a year, computed from its real price and how often the maker says to replace it. Prices are sourced and dated, never guessed.
- Why do some familiar furnace filters score lower than expected?
- When a filter is sold under an MPR or FPR number without its true MERV up front, we cap its rating-honesty score. And a high-MERV filter in a thin 1-inch panel gets flagged because it can restrict airflow. The full reasoning is on our methodology page.