Always measure the duct opening — the hole in your floor, wall, or ceiling — not the old cover. The duct opening is the size you use to order. Your new vent cover will be slightly larger than the duct opening (typically 1.25" on all sides) to overlap the surrounding surface. Measuring the old cover can lead to ordering the wrong size, especially if the original cover was a non-standard or custom fit.
Remove your existing vent cover first. Then use a tape measure to measure the width and length of the rectangular opening in inches, measuring from the inside edge of the duct on each side. Write both measurements down as width x length (for example, 4" x 10"). This is the size you order.
The duct size is the measurement of the opening in your floor, wall, or ceiling — this is what you order by. The overall size is the full dimensions of the vent cover itself, including the frame that overlaps the surrounding surface. For most standard registers, the overall size is about 1.25" larger on each side than the duct size. Always check the product page for the exact overall size if you have tight clearance around the duct.
Common floor vent sizes — 4x10, 4x12, 6x10, 6x12, 4x8, and 2x12 — are widely used in homes built after 1960. However, many homes, especially those built before 1960 or those that have been renovated, have non-standard duct openings. The best way to know if your size is standard is to measure the duct opening and check our catalog. If your size isn't listed, we make custom covers in any dimension.
Our floor vent covers are available in dozens of standard sizes ranging from 2" x 10" up to 12" x 30" and beyond. The most common sizes are 4x10, 4x12, 6x10, 6x12, 6x14, and 4x8. We also carry less common sizes for older homes. If your size is not listed in our catalog, custom sizing is available with no minimum order quantity.
Measure your duct opening (the hole in your floor, wall, or ceiling) ininches — width first, then length. That measurement is the size you order. For example, if your duct opening is 4" wide and 10" long, you order a 4x10 vent cover. The cover itself will be slightly larger than those numbers to overlap the surrounding surface.
Non-standard duct sizes are more common than most people expect — especially in pre-1970 homes and renovated properties. If your opening does not match a standard size in our catalog, we make custom vent covers in any dimension. Simply take your duct measurements and visit our Custom Vent Covers page to get started or contact us for a quote.
Flush mount wood registers come in two types: with frame and without frame. For both types, order by the duct opening size. For the flush mount with frame, the frame sits on top of the floor and the overall size is listed on the product page. For the flush mount without frame, the cover sits level with the floor surface — your installer will cut the floor opening to match the cover dimensions.
Hinged air returns are ordered by filter size, not duct size. If your filter is a 20" x 20", you order a 20" x 20" hinged air return. Standard registers and fixed grilles, by contrast, are ordered by the duct opening size. Make sure you know your filter size before ordering a hinged return.
Most standard vent covers overlap the duct opening by approximately 1.25" on all sides. This overlap holds the cover in place on floor installations and covers the rough edge of the duct cutout. The exact overlap varies by product style, so check the overall dimensions on the product page if you have tight clearance.
