10x10 Metal Wall Vents: Free Area, Airflow and Duct Fit
A 10x10 wall vent has a free area of 32.1 square inches and a calculated airflow of 111 CFM, and it drops into a duct opening of 247.7 x 247.7 mm.
- Duct opening
- 9.75″ × 9.75″
- Metric
- 247.7 × 247.7 mm
- Best free area
- 32.1 sq in
- Comes in
- Flush Wall · Framed Wall
10x10 is the only square size in the wall line below 14 inches, and at 32 percent open it is the most open wall vent wider than 6 inches.
Free area and airflow at this size
| Product | Free area | Open | Airflow | Price | |
|---|---|---|---|---|---|
| Flush Wall Vent [Metal] | 32.1 sq in | 32% | ≈ 111 CFM | from $49.99 | View 10x10 |
| Framed Wall Vent [Metal] | 32.1 sq in | 32% | ≈ 111 CFM | from $49.99 | View 10x10 |
Free area is the open cross-section air actually passes through, not the outside of the cover. How we calculate it.
Measuring for this size
The rough opening is a true 247.7 mm square, so orientation does not affect fit, but it does affect looks, because the slot runs all the way around and a square vent set even a degree out of level reads crooked against a drywall edge.
Why is the square 10x10 more open than the bigger rectangular sizes?
Because percent open is free area divided by the nominal face, and the 10x10 runs the wall line's widest slot, 23.0 mm, around its small 100 square inch face. It reads 32 percent on 32.1 square inches of free area, while the 10x30 runs the same slot width around a face three times as large and reads 23 percent on more than twice the free area.
What rough opening does a 10x10 need?
A 247.7 mm square, over a 201.6 mm square tray. Because it is square, orientation does not affect fit, but it does affect appearance: the slot runs all the way around, so a 10x10 set slightly out of level reads visibly crooked against a drywall edge or a tile line. Level it against the finished surface, not the framing.
How does the 10x10 compare with the 6x14?
The 10x10 carries 32.1 square inches of free area and 111 calculated CFM against the 6x14's 20.1 and 70. It needs a 247.7 mm square opening rather than the 6x14's 146.1 mm by 349.3 mm slot, which changes the framing entirely.
How do I measure for a replacement vent?
Measure the duct opening, not the old cover. Pull the existing vent out, measure the hole itself across the width and the length in millimetres, and match that to the duct dimension listed on this page. Vent sizes are named for the duct, so a vent called 4x10 has a face larger than 4 by 10 inches. Measuring the faceplate is the single most common reason a size arrives wrong.
What happens if I order the wrong size?
Email support@khansupply.co with your order number and the millimetre measurements of your opening, and we will work out which size actually fits and sort out the exchange. Every Khan Supply vent also carries a 2-year warranty against defects, which is separate from a fit exchange.
What does shipping cost?
Nothing. Shipping is free on every order across North America, on a single vent and on a 5-pack alike. You will get tracking by email once the order is on its way. If a vent arrives damaged, photograph the box and the part and email support@khansupply.co, Monday to Friday 9 to 5 ET, and we reply within one business day.
Every Khan Supply vent is all metal, not plastic, and ships free across North America with a 2-year warranty. If a size is wrong, email support@khansupply.co and we sort out the exchange. Mon-Fri 9-5 ET, one business day reply.
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