In Repair & Maintenance

Basic Door Vocabulary: 10 Terms You Need To Know

As an Amazon Associate, I earn from qualifying purchases. See my disclosures for more information.

As homeowners, we all know what we want our door to look like. We know that we like our neighbor’s red craftsman door with 6 windows in it or that we like the dark stained oak grand entrance with the fancy door handle on our mother’s front porch.  

The problem is communicating that knowledge.  You need to know the correct door vocabulary to tell the hardware store employee what you want. This is important not only for replacing a new front door but also for repairing damaged doors.

Basic Door Vocabulary

Door Parts in All Doors


The part of the door unit that the door hangs off of, closes against, and is screwed into the wall framing is called the jamb. There is no standard size of jamb and if you are going to replace your entire door with a new, pre-hung door unit, you absolutely MUST know your jamb size.

To figure out the size of the jamb, open the door and put a tape measure from one of the jamb to the other. Basically, you are measuring the thickness of the wall. If you don’t know how to read your jamb thickness, take a photo with your tape measure on the jamb and take that to the hardware store.

Basic door vocabulary terms

There are a few commonly used sizes. For a 2×4 wall with 1/2″ drywall on either side, you’ll need a jamb that measures 4-9/16″ in order to fit your wall appropriately.  The other common sizes are a 6-9/16″ for a 2×6 wall and 5-1/4″ for a lath and plaster wall.

Door Stop

The door stop is the part of the jamb that stops the door from swinging past its closed point. Without the door stop, your door would swing back and forth in the jamb, breaking your hinges eventually.

There are two main types of door stops. The first is a type called “stop applied” which is basically when the door stop is a separate piece of wood that is nailed onto the main part of the jamb. This type of door stop will inevitably loosen over time, especially if you live in a home where doors are slammed frequently.

The best type of door stop is called a “double rabbet” door stop. This means that the stop and the jamb were originally one piece of wood. The manufacturer then carves out the edges out to make the final profile.


Trim is a decorative piece of wood that goes around the door and covers any gap between the door jamb and the wall surface. You will frequently see these called “casing” in the hardware store. But there is no rule and you can really use anything as door trim as long as you like how it looks.

If you want to add trim or replace trim using a specific profile, please make sure that you take a piece of the profile you want to the hardware store. Unless you look at all of them for a living, you’re going to struggle to find something identical without a sample. A photo won’t hurt but it won’t help figure out the dimensions of your trim. Take a sample!


This is the hole for the door knob. There is a hole through the door that the two halves of the door knob connect through as well as a smaller hole on the side of the door where the latch goes.

Interior doors are usually bored with a single bore, for a single door knob. Exterior doors can have one or two bores, depending on if you want  a deadbolt or not.

Just like other aspects of a door, there is no standard when it comes to the bore. They can be set back farther from the edge of the door and, if there are two bores, there can be different distances between bores.

When you measure your bore, make sure that you are measuring to the center of the bore. If you need to know how far back the bore is from the edge of the door, measure from the edge of the door to the center of the bore. If you are measuring your distance between the bores, measure from the center of one hole to the center of the other hole.


The hinge is the hardware that the door swings on.  There is no standard placement, shape, or size for door hinges. If you are replacing your door with a prehung door unit, one that includes both the door and the jamb, you don’t need to know what hinges you have.

If you want to replace the door slab only, not the jamb, you will need to measure your hinge placement. Measure from the top of the door to the top of each hinge. Then measure the height of each hinge. 

Finally, you need to know the radius of the corners. There are three major styles: square edge, ¼” radius, and ⅝” radius. Square corners are sharp, 90 degree hinges, just like they sound. A ¼” radius hinge has only a slight roundness to the corner of the hinge because the curve is only over ¼”. Doors also use a ⅝” radius hinge that has the most pronounced curve.

Door Swing

Door Swing and Door Handing Chart

Door swing is something that few people notice when it’s right but everybody notices when it’s done wrong. This is what describes how a door opens. Does it swing into the room or does it swing out of the room? Does it open to the left or to the right?

Swing is best determined from outside the home or outside the home. Typical human behavior means that the hand you reach with to grab the door handle is the “swing” of the door. So, if you are standing outside a home and opening a right-handed, in-swing door, you will reach for the handle with your right hand and push the door in and to the right. If you are in any doubt at all, confirm your swing with a salesperson before buying a door.

If you are still confused, check out this video that presents door swing a little differently.

Rough Opening

The rough opening is the hole in the framing of the home that the door sits in. It is usually quite a bit larger than the door is, which allows for an installer to get the door to sit perfectly square and function well.

The width of the rough opening should be 2” wider than the door slab itself and the height of the rough opening should be 2” taller than the door slab itself. If you want the perfect fit to your new prehung door, you need to bring the rough opening measurements to the store when you buy the door.

Door Parts Only On Exterior Doors


The portion you step on when you walk through an exterior door. These are usually made of rubber or plastic but they can be made of metal or wood as well. If your threshold is damaged, the door may leak air or water.

Fortunately, thresholds are usually simple to replace if they do become broken. Do yourself a favor and prepare for the hardware store trip by measuring what the gap is between the bottom of the door and the portion of the threshold that is still intact.

There is no threshold on an interior door because a seal is not required in this instance. Interior doors may have what is called a transition strip to change flooring. Transition strips are usually kept by flooring rather than near doors in the hardware store. 


Think of the sill as the chair under a door and under a threshold. The sill is not a part of the door unit itself, but instead a part of the home’s framing. It is usually made of 2×4 framing out of kiln dried lumber. 

For doors that are going to see more weather, the sill can be made of pressure treated wood.  When installing a new door, it is vital that the sill is level. Without a level sill, your door is likely to become difficult to open or close eventually.

Weather Stripping

This is a strip of vinyl or rubber that is attached to an exterior door to make it weather resistant to both water and air.  These strips can be glued, taped, or nailed on, depending on your type of door.  The best option is actually one that presses into a groove just inside the door stop since it provides the best weather seal in the most permanent manner.

Door Repair

Door repair is tough. Maybe you don’t have the budget to completely replace the door or maybe you’re just intimidated by it. But you know what the issue is. You just need to be able to explain the issue to the salesperson.

A photo is incredibly helpful because sometimes that’s all it takes to describe the issue. But if your photo doesn’t describe it, or if you need to clarify, it will be vital to explain what’s going on.

Racked Door

Racked door? What is a racked door? Every homeowner has experienced a racked door, they just didn’t know that’s what it was called. A racked door is one that no longer shuts correctly because a home has settled. This could mean that the structure of the door itself gets stuck on the jamb. Or it could mean that the latch just doesn’t shut correctly.

Sadly, the only way to fix a racked door is to uninstall the door and reinstall the same door. Basically, you are just making the door fit the opening the way it stands now, rather than the way it stood a few years ago.

Loose Hinges

I’m going to tell you a secret that in reality is one of the oldest woodworking tricks in the book. Not only is it simple but it is inexpensive. Are you ready? Use toothpicks.

I see you wondering now. If your door hinge is a little loose from repeated slamming or just general use, you need to get those screws tighter. Take the screws out and expose the holes in the jamb. For some reason it’s almost always the jamb side screws that loosen.

Then, push some toothpicks in the hole until they’re all tightly packed. Cut the toothpicks off and reattach the hinges and screws using the original holes. The toothpicks give the screws more wood to bite into and help to tighten the screw.

Split Jamb

Sometimes, your jamb splits lengthwise. Usually it’s when somebody decides to try and kick in the door. There are various plates that you can purchase which you can use to quickly and temporarily fix the problem.

However, ultimately, the only solution for a split jamb is to replace the entire jamb leg. Without replacing the jamb leg, you’re going to have a door that is structurally unsound. It will have difficulty closing or opening. It will be less weather sealed. And it is less safe. Replace the jamb leg.

Final Thoughts

There are many pieces and parts to a door since the door has become more complicated than the cloth hung in the opening to a cave.  A door is a complex unit and each piece needs to work together for it to function appropriately.  

With the correct door vocabulary, you can communicate your issues with a broken door easier and you can buy a new beautiful entrance easier. Double check your information and have everything figured out before heading to the hardware store to buy a door for the easiest trip.  The salespeople will be happy to help you if you have questions and some photos though.