Let’s talk about doors. They are: a welcoming and inviting face that lets you know you’re home every night, the last hand you shake each morning before you step outside, and an essential piece to provide your retreat, and each room within it, with the privacy and safety you need to protect what’s most valuable to you.

Front doors are typically the focal point of any facade. You’ll want to select the right color, style, and material to make yours stand out. When shopping for doors, you’ll find a wide variety of options —paneling, luxury handles, you name it. However, there’s a lot more to it. You must always consider the value for money. Pick a piece that meets your particular needs while reflecting your personality.

Just like any other part of a building, doors, too, have a limited lifespan. After all, they endure a lot more than we credit them for. We open and close them time and time again, repeatedly knock on them, and occasionally even slam them. On top of all this, doors also withstand the elements and the passage of time. It’s only natural that, at some point, they’ll begin to deteriorate.

If your exterior doors have seen better days, perhaps it’s time to call a reliable provider like US Window & Door for help. However, before you start shopping for a substitute, you’ll need to figure out the required dimensions. Keep reading for our guidelines on how to measure an exterior door for replacement.

Door Replacement Done Right

High-quality doors are an excellent investment. Not only are they a must-have for the security and privacy reasons we mentioned earlier, but they can also make a huge visual impact on your exterior landscape. At the same time, doors minimize your home’s vulnerability to weather variances. They help keep your oasis the perfect temperature; either warm and dry or cool and breezy.

Some doors come with added characteristics to suit your particular needs. They may make your house energy-efficient or block unwanted noises. However, all these benefits are useless if you get the wrong size pieces. You need to make sure your new door fits the opening in the wall just right to avoid any unfortunate malfunctions. This way, you’ll undoubtedly take full advantage of any extra features.

As intimidating as it might seem, getting the dimensions right is not such a complicated task. But before we learn how to measure for a door replacement the correct way, there are a few points we need to cover.

Doors 101

First things first. Before you take out your measuring tape, there are two main kinds of doors you’ll have to get acquainted with. When visiting any showroom, you’ll most likely find yourself choosing between prehung doors or door slabs. Let us explain the main differences between them.

When you find an entire unit that consists of a door that’s already mounted with hinges to a full jamb frame, you’re looking at a prehung door. If you get an interior one, it’ll only include the side and top jambs. However, exterior prehung doors might also come with a door sill, a threshold, or a decorative trim. Some of them might even include a brick mold, which you may easily replace with any other molding of your liking.

You can also purchase a replacement door without the frame or the joints. We know this as a door slab. This option is a lot easier to install since it doesn’t require you or your contractor to unmount the whole structure. However, if your previous door jambs are already worn-off, we recommend going for a prehung unit instead.

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Here are some other terms you’ll have to get familiar with when shopping for replacement doors:

♦ Rough Opening: This is the structural hole in your wall that’ll accommodate your new door. If you choose to replace the whole frame, you need to purchase one that’s 1/2 to 3/4 inch narrower and about 1/2 inch shorter than the rough opening.

♦ Door Frame: Also known as the jamb frame, it’s the wood structure that the door slab will hang from. On exterior doors, it consists of side jambs, a head jamb, and a threshold. Interior door frames typically only come with the side and top jambs.

♦ Stops: That’s how you call the narrow strips nailed inside the jambs. These pieces create the inner frame that the slab closes against. They prevent the door from swinging inwards or outwards, depending on the direction you want it to open.

♦ Casing: The trim that covers the gap between the frame and the finished wall. Basic doorway casings consist of three separate pieces to back both sides and the top.

Allowing some room between the door frame and the rough opening gives you the possibility to fit it and square it up before the installation. Once the door is in the right position, you must fill the small gaps between the jambs and the wall with tapered shims. Doing this will keep your structure in place as you fix it to the opening. Once you’ve correctly placed the door, you can always cover the gaps around it with decorative casing.

Metric vs. Imperial System

When you use the imperial system on a daily basis, it’s easy to assume it’s the standard when you measure for replacement doors. While using it is not entirely wrong, it might give you a hard time dealing with smaller units. You’ll inevitably end up using fractions of an inch, which might make it harder to come up with a precise number.

However, there is a more accurate way of getting your measurements just right. The metric system allows you to go down to millimeters, which is rather useful when determining your door’s correct size. Nevertheless, make sure you check in with your provider first. They might already have a preferred system to work with. Whatever the case is, it never hurts to measure two or three times to be sure you’re good to go.

If you don’t feel comfortable taking the measurements or have any questions, don’t hesitate to contact an expert. This way, you can rest assured that you’ve placed your door installation in the right hands. At US Window & Door, we have trained technicians qualified to do the entire process for you.

Measuring for Replacement Doors Step by Step

As we mentioned earlier, there are two methods to replace a door. One is by changing the slab, and the other one is by supplanting the entire unit. Both scenarios require different techniques to determine the correct dimensions. While our installation experts will handle the complete removal of your existing door and set up the new one, let’s break down the many ways to measure for replacement doors.backside to determine the door’s thickness.

In case you’re planning on adding hinges, a lockset, or a deadbolt to your slab, you will need to do the following:

♦ Measure the distance from the top of the door to the top of the first hinge.

♦ Measure the distance from the top of the door to the top of the second hinge.

♦ Measure the distance from the top of the door to the top of the third hinge.

♦ Measure the distance from the top of the door to the top of the fourth hinge (for 96” doors).

♦ Measure the width and height of the hinge you are using while it’s open.

♦ Measure the distance from the top of the door to the center of the deadbolt.

♦ Measure the distance from the top of the door to the center of the lockset.

♦ Measure the distance from the edge of the door to the center of both the deadbolt and the lockset. They should be the same.

On the other side, measuring for an entire prehung unit is a slightly different story. First, you’ll need to remove the casing. Doing this will help you see the backside of the frame. Once you’ve done this, you’ll only need to calculate the height and width of your entire rough opening. As you know now, a prehung door consists of the door and its frame. That’s why your measurements pertain to the jambs and not the slab.

If you’re only changing the board, you’ll finish before you know it. Door slabs sizes are quite simple to figure out. You’ll hardly ever require an expert to do it for you. All you’ll need to do is measure the height and width of the piece you are replacing. However, make sure you do it from the backside since it’s slightly larger than the front.

Here are the steps to follow:

♦ Close the door and stand behind it. You’ll know you’re on the right side if you can see the hinges.

♦ Measure the width of the door.

♦ Continue by measuring the height.

♦ Open the door and measure its thickness.

If your old piece is not the right size or if it’s missing, you can always measure the frame. Do it this way:

♦ Measure the width of the inside of the jambs at the top, middle, and bottom sections.

♦ Measure the frame’s height from the floor to the top jamb’s bottom face.

♦ Measure the distance from the portion of the jamb between the stops to the frame’s

If you’re replacing an existing unit, you’ll need to remove the trim on either side of the door and do the following:

♦ Measure the width of the door frame from the outside of the jambs.

♦ From the bottom of the threshold to the top jamb’s highest edge, measure the door frame’s height.

♦ From the interior edge to the exterior trim, measure the width of the side jamb.

♦ Measure the width and height of the trim frame on the exterior side of the door.

And lastly, if you’re purchasing a brand new prehung unit for an empty rough opening, you’ll need to follow these steps:

♦ Measure the width of the rough opening from the inside faces of the side posts.

♦ Measure the height of the rough opening from the floor to the bottom face of the header.

♦ Measure the thickness of the wall.

On a side note, make sure to confirm the swing’s direction before placing an order for your replacement. Meaning you’ll need to figure out whether your door opens left or right. This step is especially important when shopping only for slabs to install on a pre-existing frame. Otherwise, you’ll end up wasting time and money on a door that might not be compatible with your current setup.

Doors You Can Trust in San Diego

Replacing your doors by yourself is no “mission impossible.” However, it’s preferable to hire a knowledgeable technician to do it for you. It’s the best way to achieve your desired results without too much hassle. Although it might seem like an additional expense at plain sight, it’ll save you lots of time and money in the long run. Besides, many companies offer a free consultation to answer all your questions.

If you are a homeowner or a contractor in San Diego, US Window & Door is your best solution for door installation. We’ll take care of every detail, from taking measurements to installation and maintenance. Our many years of experience working with HOAs and development management companies reinforce our qualifications.

We are Milgard and Masonite exterior door providers, and we offer only premium quality products. Our selection of stylish fiberglass products will make your facade stand out and increase the curb appeal of your property. Milgard and Masonite strive to be sustainable brands. Not only will you get gorgeous doors, but you’ll reduce your carbon footprint while you’re at it.

Contact us today for a free estimate, and let us team up with you to unleash your home’s full potential!