Furnace filters: does actual size equal the label?
Actual size is smaller. All twenty Filterbuy filters measure 0.5 in under nominal length and width; a 16 x 25 x 1 in example measures 15.5 x 24.5 x 0.75 in.
MERV choices change with thickness.
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With no preferences selected: 16x20x1 MERV 8 Pleated Air Filter is one option to compare.
Your choices are compared with each model’s product details. A missing or conflicting value stays unknown and cannot satisfy a choice you select. The starting order helps you browse; it does not rate real-world performance.
Source dates appear with each link below. A source date does not confirm today's price or stock.
16x20x1 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x20x1 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x20x1 MERV 8 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x20x2 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x20x4 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x25x1 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x25x1 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x25x1 MERV 8 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x25x2 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
16x25x4 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x20x1 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x20x1 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x20x1 MERV 8 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x20x2 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x20x4 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x25x1 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x25x1 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x25x1 MERV 8 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x25x2 MERV 11 Pleated Air Filter: Source 1 ↗ · September 26, 2026
20x25x4 MERV 13 Pleated Air Filter: Source 1 ↗ · September 26, 2026
The size on the frame is not the size of the frame
Filterbuy's nominal 16 x 20 x 1 in filter measures 15.5 in by 19.5 in by 0.75 in. Across the comparison, actual depth runs from 0.75 to 3.63 in. Start with the equipment's specified filter size, then compare actual dimensions with its slot. A nominal match alone cannot prove that the filter fits or seals correctly.
Choose filtration within the furnace's airflow limits
Filterbuy's MERV ratings span 8 to 13. The same nominal size appears at different ratings, so dimensions do not settle filtration choice. Use the equipment maker's permitted filter specification. Airflow resistance in your system cannot be read from product dimensions and MERV labels; pressure drop and particle removal through these filters remain unmeasured.
Keep the size variant attached to the order
All 20 filters have nominal and actual dimensions, but the thicker Filterbuy variants still need their own depth comparison. Carry the complete size and MERV rating into checkout. Package quantity and the replacement schedule are separate details; neither follows from the dimensional fields. Follow the equipment instructions for access and replacement rather than selecting an interval from filter thickness.
Before you buy
Is a higher MERV rating better for my furnace?
This page can't answer that for your system. Filterbuy's pages here give size and MERV but no airflow or pressure-drop figures, so the MERV your equipment maker allows is the limit this finder works to.
Do these come in multipacks?
Probably, since Filterbuy's pages show quantity pricing, but pack sizes and prices aren't compared here, so the per-filter cost is on the product page you open. Only the 1 in filters have it; the 2 in filters come only as MERV 11 and the 4 in only as MERV 13.
What if my size isn't here?
These 20 cover four face sizes (16 x 20, 16 x 25, 20 x 20 and 20 x 25 in) at three thicknesses, and the middle and thickest nominal groups measure 1.75 in and 3.63 in deep respectively. Other sizes aren't part of this comparison, and Filterbuy could still sell yours; take the nominal size from your current filter and look for it by name.
