Your Guide to Vent Cover Sizes: Standard, Custom & Hard-to-Find Dimensions
Whether you're remodeling a century-old home or outfitting a new build with premium finishes, vent cover sizing is a crucial detail that can’t be overlooked. At Reggio Register, we believe craftsmanship lives in the details — and that includes getting the exact right fit.
In this guide, you’ll find everything you need to choose the perfect size vent cover, from standard vent cover sizes to our ever-expanding selection of custom grille sizes. Bookmark it — this is your go-to resource for all things register sizing.
Standard Vent Cover Sizes: What You Need to Know
Most HVAC registers follow a set of common sizes — especially in newer builds. These are generally easy to replace with stocked options.
Common Standard Sizes
- 4" x 10"
- 4" x 12"
- 6" x 10"
- 6" x 12"
- 8" x 8"
- 10" x 10"
These measurements refer to the duct opening size, not the outer dimensions of the cover. At Reggio Register, our product pages clearly differentiate between duct size and faceplate size, so you're never left guessing.
Pro Tip: Always measure the duct opening, not the old register, especially if it has a decorative lip or border.
Vent Cover Size Chart
Here’s a quick reference for the most requested sizes:
| Duct Opening Size | Typical Use | Available at Reggio Register |
| 4" x 10" | Bathrooms, hallways | In stock – only in stock in Scroll Vent Grille and Square Vent Grille |
| 6" x 12" | Bedrooms, home offices | In stock – only in stock in Scroll Vent Grille and Square Vent Grille |
| 8" x 8" | Kitchen, utility rooms | ️ In stock- only in stock in Scroll Vent Grille and Square Vent Grille |
| 10" x 30" | Open floor plans | Now available! |
| 16" x 16" | Large intake returns | Now available! |
| 20" x 20" | High-capacity systems | Now available! |
Explore even more new sizes below.
These Sizes Now Available — Built for Modern & Legacy Spaces
Our product line continues to evolve based on real-world requests and emerging design needs. These sizes offer expanded design possibilities:
- 4" x 24"
- 6" x 8"
- 8" x 16"
- 8" x 24"
- 8" x 30"
- 10" x 30"
- 14" x 20"
- 16" x 16"
- 20" x 20"
These sizes are now part of our standard inventory — no custom request required. That means shorter lead times and more flexibility for your project planning.
Retrofitting Older Homes: Challenges & Solutions
Homes built before 1950 often have non-standard vent openings, sometimes by fractions of an inch. You might find:
- Odd dimensions like 5.75" x 13.25"
- Vents installed directly into baseboards
- Wall openings that have shifted or settled
That’s where Reggio Register’s custom vent cover sizing comes in. We craft covers down to 1/16" accuracy using premium materials — including laser-cut steel, laser-cut aluminum, laser-cut solid brass— so you can preserve the integrity of your home without compromise.
Need help measuring a custom grille? Use our measuring guide or contact our expert care team.
Customization Options That Go Beyond Size
Register sizing is just the beginning. At Reggio Register, we also offer:
- Thickness adjustments (for flush or surface mounting)
- Finish selection (from Oil-Rubbed Bronze to Satin Nickel)
- Pattern choices (classic scrolls to modern minimalist)
- Mounting solutions (screw holes, no holes)
- Optional underside lip for secure floor mounting
- Beveled edges for the perfect finish
Whether you're matching a historical design or creating a contemporary look, we make it yours — down to the last detail.
How to Measure Wall and Floor Vent Covers (Correctly)
1. Remove the old grille.
2. Measure the duct opening — height first, then width. Do NOT measure the faceplate — this can vary by brand.
3. Check depth and clearance, especially for floor vents.
Need help? See our step-by-step guide or talk to a real person — our expert care team is always available.
Frequently Asked Questions
What if I can't find my size online?
We can custom-make almost any size — just submit your measurements or give us a call.
Do the sizes listed on the site include the outer frame?
No. All dimensions refer to the duct opening size unless stated otherwise. We list both duct and faceplate sizes clearly.
Can I return the register if it doesn’t fit?
Yes, as long as it’s in original condition. Custom orders are non-returnable, but we’ll help you measure right the first time.
Are all your sizes available in all finishes and materials?
Most new sizes are available across our full range of materials and finishes. Look for availability notes on the product page.
Built to Fit. Designed to Last.
At Reggio Register, we believe every detail matters — and that includes getting the right size vent cover for your space. Whether you're choosing from our growing collection of stock sizes or customizing a piece to match your vision, our registers are built to elevate your home’s design and performance.
Ready to Find Your Perfect Fit?
Explore our full collection of vent covers or talk to a customization expert today.
