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A Handy Guide to Measuring a Door for Replacement

PostedbyPella Windows & Doors of Nashville

on August 11, 2022

Doors are an essential part of your Nashville property for maintaining your privacy and safety. However, because of their constant use, they are prone to damage over time. Their hinges may start falling off, holes and cracks may start appearing or they can simply look old and worn out. Since the structural integrity of your doors is so important, a door replacement is your best option in these cases.

However, you don’t just go to your hardware store and choose a new door without any preparation. You could end up with something too large or too small and end up wasting both your time and money. Before you go shopping, you need to take accurate measurements of your door.

Here are some tips for getting the numbers you need.

What You’re Going to Need

Before going through with your door replacement, you need to gather the equipment you’re going to use for measuring. These will make the process easier and allow you to get accurate values.

  • Tape measure. These handy rulers allow you to easily measure the length, width and thickness of your door. The standard 12-foot ones will do since regular doors don’t usually exceed this length.
  • Notebook and pen. Record your measurements in something that you won’t easily lose, like a favorite notebook. You can also use the notes app on your smartphone.
  • Ladder or chair. The tops of doors are sometimes higher than your arm’s reach. A sturdy chair or stepping ladder will help you reach all the way up for accurate measurements.

Door Parts and Terms to Know

You also want to know the names of the parts you’re going to measure. This knowledge will help you make more precise notes to reference while shopping. Having the language to discuss this will also enable you to ask employees at the showroom for additional guidance.

  • Door Slab: The door slab is the solid piece of wood that makes up the body of your door, without any accessories like hinges or trims. 
  • Hinges: Hinges are the moving metal fasteners that attach the door slab to the frame, allowing you to swing the door back and forth.
  • Trim/Frames: The frames are where the hinges of a pre-hung door are attached. A trim is a frame used for exterior doors. However, these can be used for interior doors for aesthetic purposes.
  • Jamb: A jamb is a single frame piece located on each side of the door.

Slab Door

Pure slab doors are usually utilized for interior rooms. These are free from any decorative trims, making them the easiest to measure.

  • For the door’s width, stand on the inside side of the door — where the hinges are visible. Measure from the left side of the slab to the right, making sure that your tape is level.
  • Do the same from top to bottom to measure the length. 
  • If you’re worried that there’s warping, take several measurements aside from the center.
  • Measure the thickness of the door by measuring the width of both the slab and the jamb. These two numbers should be similar, if not the same.
  • Optional: You can also measure the frame’s height and width as an added reference.

Pre-Hung Door

There’s a slight difference in measuring pre-hung doors, but these follow the same principle as slab doors. Pre-hung doors are the ones used for entryways that don’t have pre-existing doors. Still, you can measure an existing one if you’re planning to have it replaced.

For First Installs

Measure the height and width of the opening. Make sure to take several measurements and choose the shortest one. Find the depth of the entryway by measuring the thickness of the wall.

For Replacements

Remove the trim using a pry bar. This will help you ensure that you’re only measuring from the door frame. Then, measure the height and the width of the frame by placing the tape measure on each edge of the jamb.

For the thickness, measure from the outer edge of the jam towards the inner edge. Don’t include the trim, since the door slab won’t close to that part.

Sliding Door

Sliding doors are less common than hinged doors, but measuring them is almost the same. What you need to remember is that these cover the whole entryway and usually don’t need trims.

  • Measure the height from the point that meets the header all the way down to the floor.
  • Measuring the width should follow a similar process, with you measuring from left to right or vice versa. 
  • Measure from the outside. If it’s an entry door, the outside would be where the lock is. It’s the reverse if it’s an interior door.

Go Shop for Your New Door

Now that you have your measurements, you can visit our Franklin showroom and find the right door for your home! Our Pella of Nashville showroom is a good place to check since we have a wide variety of doors available. If you’re not 100% confident about your measurements, our team is ready and happy to do everything for you, from measurements to replacement.

Or, you can schedule a free in-home consultation for one of our Pella professionals to discuss your door replacement options with you and answer any questions.

Schedule a free consultation to find windows and doors for your home.