Guide: How to Accurately Measure your Vent Cover Size and Avoid Returns?

Have you been dreaming of changing that old, rusted vent in your room? But can’t find the size anywhere? Consider this your blueprint for vent covers.


After months of procrastinating, you finally embark on your journey to renovate that room one bit at a time. You find the best flooring, perfect wall paint color, and beautiful décor but are still stuck with the ancient-looking piece of metal that covers the hole in the floor or wall of your room. You have been to Home Depot many times just to find the right size. But they just don’t seem to have the size you need for your duct opening. Wait…..are you even measuring your duct opening? Or are you measuring the outer size of your old vent cover?

 |“Measure twice, buy once”

Ahh….caught you!! You must’ve measured the old vent cover and are now stuck with it since you lost the bill or maybe it’s just too late for a return now. Let’s see how this can be avoided.


What Are Floor Vent Registers Used For?

Floor registers are a necessary investment in today’s time. They have a high demand in the market and can easily change the whole look of your room. These vent covers are often installed in the interior of the house and happen to change the look significantly.  Apart from changing the look of your room, a heat vent cover is necessary as it allows forced heating to come out of the duct. In some areas, of your home, you might also find a cold air return which is a cover to simply pass air out without the louvers at the back. The dampers on registers open and close the flow of air, whereas they do not exist on returns.

In all homes, vents come in a wide variety of sizes and shapes. We understand that it can be a little tricky when it comes to measuring your vents, that’s why we have created a guide for you to make the process as easy as possible. Vent covers made from cast aluminum are lightweight and durable, as well as we add an extra layer of rust-free protection by Powder Coating the pieces including the damper. You can shop from our existing range of floor registers and air return grills available in standard duct sizes or get send us your duct opening measurements and get a customized size made. These vents are exquisitely sand-casted in three kinds of metals to choose from including; Cast Aluminum, Steel, and Solid Bronze. Read more here on the type of metal you could choose for your vent cover/ grill.

In case, you are getting a customized vent/ grill you may also send us your design and we would custom-make it for you, to make a great addition to any room.

how to measure vent cover size guide

Step 1: Remove the existing air register or vent cover

This is the first step before you get into measuring the duct opening size. You need to hold the cover in the middle and carefully remove all the screws using a screwdriver for a wall vent cover, and simply lift the cover using your two hands, in case of a floor register. If you are not able to get a proper hold of the cover, just use a flathead screwdriver to hold it and remove the screws. If your vent cover does not have screws, then it will be easier for you to remove it. You can remove the vent cover as shown in the video below:



Step 2: Measure the size of the duct opening

Before ordering your new vents, you need to make sure that you are not ordering them by the size of your existing vent cover and measuring the actual duct size. Measure the duct opening size whether it’s on your wall, floor, or ceiling accurately before ordering. You need a measuring tape to do this step. The correct method to measure it will be Length in inches X Height in inches and there is no other way to measure the duct opening size. The length (L) is always expressed first followed by the dimension of height (H). It is important to follow this order since many of the vent covers include directional patterns. The correct way to measure the size of the duct can be seen in the picture below:

 measure the inside duct opening measurement

Step 3: Match your duct opening size with the product size you are planning to buy

This is the final and also the most important step in the process of getting the right vent cover for your home. For this, you have exactly match the duct opening size that you have measured with the corresponding vent cover size listed on the product listing. The length and height of your duct should exactly match the length and height of the listing that you are looking to purchase in order to perfectly fit the duct at your home. The size that you have measured and the size given on the listing page is the inside measurement of the opening and the overall (outside) size of the cover will be larger than the opening size. The reason for this is the outside border portion of the cover where screw holes are placed. Also, the dimension of the cover back frame will be slightly smaller than the size you have measured to ensure that the frame fits comfortably inside the duct opening. You can see more in the picture given below:

 how to measure vent cover

How to measure in the case of a Baseboard Cover?

You should place your order based on the size of the hole opening in your baseboard area. For example, if your hole measures 6”x12” then make sure you get the 6"X12" Baseboard Vent Cover Grille in Solid Cast Aluminum with an Overall faceplate size of 8”x14”. The outer faceplate dimensions will be greater than the duct opening as this area would have counter-sunk screw holes in order to mount the grill in place. 

Mistakes to avoid while measuring your Vent Cover size

The most common mistake we tend to make is taking a measurement of the old/ already installed vent cover without even removing it from the duct opening. This causes a lot of confusion as when you go to purchase the new cover, you use the overall face plate size of your existing vent and not the duct opening size, which is incorrect. Another reason we recommend you take the cover off is because the outer size of your grill/vent can vary from company to company as some manufacturers keep a ½” border whereas others might keep a 1”. Measuring the inside; duct opening size avoids such confusion.

A little suggestion would be to always check the specifications on the website you are purchasing from since as I mentioned before different companies could have different overall sizes, that could lead to the hassle of exchanges and returns in the end. You can find that the overall dimensions of your required size will be listed on the product page of each item/ website.

mistakes to avoid while ordering vent covers

How can Registers & Hardware help you?

We hope that the information in this blog will help you measure the correct size of your duct and get the right vent covers for your home. By measuring the correct size, you will be one step closer to finding the right air vent you've always dreamed of! This will make your home look much better. 

At Registers and Hardware, we offer multiple standard sizes so that you can find the right size air vent. What if you don’t find the right size air vents for your duct? Don’t worry, We’ve got you covered. We also offer custom vents in aluminum as well as bronze so you can get the size that you want in the designs you like.