Standard Fireplace Sizes and Dimensions, and How to Choose the Right Size for Your Home

There are few things more relaxing than retiring for the night in front of a cozy fireplace. Whether you need to replace your existing fireplace or you’re considering installing one for the first time, getting the right fireplace size is important for aesthetic, safety, and legal reasons. Understanding average fireplace sizes and where you can customize is a good place to start the process.

What Is the Standard Fireplace Size?

There is no universally standard fireplace size because the dimensions vary based on the type of fireplace, aesthetic preferences, and space restrictions. Electric fireplace sizes vary infinitely, but wood-burning and gas fireplaces are normally between 24 and 36 inches tall, 30 to 48 inches wide, and 13 to 20 inches deep.

Fireplace Size by Type

You may be considering a few different types of fireplaces, and the one you choose will affect the minimum dimensions allowed by building code and the dimensions that are standard.

Standalone Electric Fireplace Size

Standalone electric fireplaces are a convenient way to create the look and feel of a fireplace without investing in venting, masonry, and gas lines. These units normally include an electric fireplace insert inside of a faux hearth and fireplace surround. They often have the same height and width as a wood-burning fireplace but can be smaller and much shallower because there are no building code requirements.

Wall-Mounted Electric Fireplace Size

Wall-mounted electric fireplaces create a modern or contemporary aesthetic in your home, and they’re highly customizable because there are no building code requirements limiting your fireplace design. They typically need a depth of 4 to 6 inches, but the height and width are totally customizable.

Wood-Burning Fireplace Size

Wood-burning fireplaces are usually 36 to 42 inches wide, 24 to 30 inches tall, and 16 to 20 inches deep. There are strict building code requirements for most parts of the fireplace that vary based on what materials your fireplace is made of. Brick and solid masonry are the most common options.

In addition to height, width, and depth requirements, you’ll also need to abide by building code for flue diameter, hearth thickness, chimney size, chimney wall thickness, and the distance from the firebox to any combustible materials, including finished flooring, fireplace mantels, and more.

Gas Fireplace Size

Gas fireplaces tend to be a little smaller than wood-burning fireplaces, largely because they don’t have varying flame levels. The average gas fireplace—whether it uses natural gas or propane as a fuel source—is between 30 and 48 inches wide, between 24 and 36 inches tall, and between 13 and 18 inches deep.

Since gas fireplaces still involve combustion, you’ll also have restrictions related to the size and placement of your ventilation system, chimney size, hearth thickness, and distance to combustible materials. These added dimensions can vary based on how your gas fireplace is vented.

Outdoor Fireplace Size

Outdoor fireplaces vary more in size than indoor fireplaces because you can choose any fuel source that suits you, and you have far fewer restrictions for the firebox dimensions and ventilation. You also have fewer space restrictions since your fireplace and hearth won’t be intruding on living space, so you can build a fireplace that suits your preferences without many limitations.

Factors That Influence Fireplace Size

There are many factors that you should consider when deciding on a fireplace size that suits your home.

Type of Fireplace

The type of fireplace you want to install is one of the most important factors to consider, as it will dictate the minimum size allowed in your space. Electric fireplaces can be just about as small or as large as you want them to be, while gas fireplaces and wood-burning fireplaces have strict building code requirements for sizing that you’ll have to abide by.

Chimney Size

If you’re replacing a fireplace that vents through or sits in a chimney, the size of your chimney is an important consideration to make, as it will often dictate what size fireplace looks good. Chimneys extending from the floor to the ceiling give you much more freedom regarding fireplace height. Your flue size will still limit the width, unless you choose an electric fireplace insert, in which case your options are only limited by the size of your wall.

Room Size and Space Constraints

It’s a good idea to consult an interior design professional to decide what size fireplace would match the room. Generally speaking, your fireplace will look proportional if the fireplace surround takes up no more than 50% of the wall, and the firebox width is 50% to 70% of the width of the surround. These aren’t requirements, though, and some homes may benefit from breaking these rules of thumb.

Building Code

Wood-burning and gas fireplaces are inherently dangerous, so there are dozens of building code requirements for these types of fireplaces. You should hire a fireplace professional when designing your fireplace, as you’re likely to run into restrictions for all of the following:

• Firebox width

• Firebox height

• Firebox depth

• Chimney wall thickness

• Chimney material

• Hearth thickness

• Hearth material

• Distance from firebox to combustible materials

• Flue diameter

• Ash collection

• Mantel height above firebox

These regulations will dictate the minimum and maximum size of your fireplace in all cases, depending on the room where you’re installing your fireplace.

Budget

Finally, your budget will play an important role in your fireplace size. No matter what type of fireplace you’re installing or replacing, bigger sizes will mean more materials and more labor required to get the job done, which means a higher cost of installing your fireplace.

Speak with a professional about your budget and preferences to see what size fireplace you can comfortably afford.

What to Do if You Have the Wrong Size Fireplace

A fireplace should add to the look and feel of your room or outdoor area, and it often boosts home value, but if you find that you have a fireplace that looks awkwardly small or takes up too much of your wall to be convenient, you do have some options for fixing the issue.

If your fireplace is too big, you can consider a fireplace insert to downsize the size of your firebox slightly, which may fix the issue. If it’s much too large, though, you may need to hire a fireplace professional near you to make it smaller while abiding by building code regulations. Removing a wood-burning or gas fireplace and replacing it with an electric fireplace is probably the most affordable option, so that’s something to consider if you’re on a tight budget.

If your fireplace is too small, you’ll also need to consult an expert to see your options. Fireplace remodeling costs to expand a wood-burning or gas fireplace will be expensive because you’ll likely need to expand the chimney, replace the flue, and potentially make structural changes to your home to accommodate a larger fireplace.