A precise fit starts with the opening, not the visible cover. Before ordering a floor vent, measure the duct opening and check the installation dimensions for the specific model you plan to use.
1. Remove the existing register, if safe to do so
Lift out a loose register to expose the opening. If it is fastened, sealed or built into the floor, do not force it. Ask your installer to help identify the opening without damaging the finish.
2. Measure the opening in both directions
Use a tape measure to record the inside width and length of the duct opening at floor level. Measure edge to edge, rather than across the outside of the old cover. Check both ends if the opening is irregular, and record the actual measurements rather than rounding to a product size.
3. Separate nominal size from frame dimensions
A nominal vent size, such as 4" × 10", generally identifies the intended duct-opening size. It is not the outside size of the frame, and it is not a cutting template. Compare your measurements with the selected product's dimension sheet before ordering or making cuts.
4. Check the surrounding floor
Record the flooring material, finished flooring thickness and clearance to walls, trim and other obstructions. Flush vents also need space for the frame and a compatible flooring insert. Ask your installer to confirm the required opening, support and finished height for your chosen model.
Before you order
Keep a photo of the uncovered opening, its measured width and length, and your flooring details together. If the opening is uneven, inaccessible or between nominal sizes, confirm compatibility before buying. Do not enlarge an opening simply to match a product name.
Not sure what you measured? Contact VARE with your measurements, photos and flooring details before ordering.