How to Measure for Electric Fireplace Insert (Tutorial)

If you appreciate the comfort of an open fire in your fireplace but aren’t thrilled about how costly and inefficient it can be, then it might be time to convert to an electrical fireplace. Switching your existing fireplace to a more efficient electric one is an easy task with an electric fireplace insert.

But before you go shopping, you’ll need to know what size of electric insert you’ll need. And to do that, you’ll need to make a series of specific measurements to ensure a proper fit. But don’t worry, we’re here to show you how to measure for an electric fireplace insert. Let’s get started!

What You Need

Before you start, gather the tools you’ll need. This is a relatively simple project, so you only need three items:

measuring tape
notepad
pen or pencil

How to Measure a Fireplace

Measuring a fireplace is a little more complicated than just measuring the height and width at the front of the opening, the part of the fireplace known as the face. Fireplaces are often built with angled walls, so if you only took measurements of the face, you may find that one part is smaller than you assumed.
To properly measure your fireplace, you will be recording the height, width, and depth of your firebox. The firebox is the opening in your fireplace where you would build a fire.

You want your fireplace insert to fit properly, so accurate measurements are critical. Grab your tools and head over to your fireplace. Make sure you keep that notebook close by — you’re going to be writing down these measurements at each step.

Step 1. Measure The Height

You need to take three different height measurements.

First, you need to measure the height of your firebox at the opening.
Then you need to record the height at the back of the firebox.
Lastly, you need a measurement from the lintel — that’s the horizontal iron piece above the firebox opening. It gives the fireplace extra support. You can’t always see the lintel. Sometimes it’s embedded in the fireplace brickwork, but if your lintel sticks out a little bit, add 1/8″ to your measurement to allow for clearance.

If the opening of your fireplace is arched, you need to record the size of the opening at the highest and lowest points.

Record each of those results in your notebook, then proceed to step two.

Step 2. Measure the Width

As with the height, you’ll be taking at least four different measurements, possibly more depending on the geometry of your firebox.

Measure the width of the front opening at both the top and the bottom.
Measure across the back wall of the firebox at both the top and the bottom.
If your firebox is angled, make additional measurements as needed.

All the different measurements here help to verify that your firebox is true to square. If your firebox is square-shaped, you should have the same width across the top and at the bottom. But if your firebox is angled, you’ll have a series of different numbers. In that case, pay close attention to the smallest numbers (you’ll learn why in a moment).

Write your measurements down and move on to take the last measurement.

3. Measure the Depth

The last measurement you’ll need to know is how deep your firebox is.

From the center of the firebox, along the bottom, measure from the front of the opening to the rear wall

As before, record the results.

4. Ensure Accuracy

You should now have at least five measurements recorded: opening height, rear height, opening width, rear width, and depth along the bottom. If your fireplace has an arched opening or an angled firebox, you may have recorded a few more measurements.

When choosing a fireplace insert, you’ll always use the smallest measurement to ensure the best fit, especially if your firefox is angled. If you didn’t measure properly, you may have to force the insert into place or even modify the fireplace opening.

That’s It!

An electric fireplace offers all the benefits of a traditional fireplace but is much more energy-efficient. As you can see, outfitting an existing wood-burning fireplace with an electric fireplace insert is as simple as taking a few measurements.

If you have any questions about how to measure your firebox to fit for an electric fireplace insert please post in the comments. And if you found this article interesting, please share it on your social media channels.