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How to Measure Your Fireplace Space

If you're thinking of getting a new fireplace or upgrading your old one, you might be wondering how to measure your fireplace space correctly. You’re not alone. In fact, this is one of the top concerns when someone buys a fireplace or an insert. It totally makes sense—you want that insert to fit just right!

How to measure your fireplace correctly

To measure your fireplace space correctly, you'll need to measure its height, width, and depth. But remember, it's not just a single measurement that'll do the trick! You've got to measure at different points to get accurate measurements. Check the opening, the back, the floor, and the top of the firebox.

Image of Modern Flames Redstone 36-inch Built-in Electric Fireplace Insert

In photo: Modern Flames Redstone 36-inch Built-in Electric Fireplace Insert

First, you'll need some tools: a tape measure, a pencil, a piece of paper. You might also want to have a level, a flash light, mirror, and a ruler handy, just in case. 

Get the standard measurements

Step 1: Measure the width of your fireplace opening. This is the distance from one side of the opening to the other. Make sure you measure at the widest point, which is usually near the top. Write down the measurement on your paper.

Image of width of fireplace opening

Step 2: Measure the height of your fireplace opening. This is the distance from the bottom of the opening to the top. Again, measure at the highest point, which is usually near the center. Write down the measurement on your paper.

Image of the height of fireplace opening

Step 3: Measure the depth of your fireplace opening. This is the distance from the front edge of the opening to the back wall of the fireplace. You might need to use a flashlight or a mirror to see inside. Write down the measurement on your paper.

Image of the depth of fireplace opening

 

 

Measure your fireplace correctly, based on type

Fireplace inserts

Fireplace inserts are sealed boxes that fit into existing fireplaces to improve their efficiency and appearance. They can be powered by wood, gas, or propane, depending on your preference and/or fuel availability. 

Fireplace inserts come in different sizes, ranging from small to large, to suit various firebox dimensions. The width, height, and depth of the fireplace insert should match the measurements of the fire opening, the front opening, and the depth from the front to the back of the fireplace cavity. 

Image of fireplace measurements

For inserts, you have to measure the dimensions of an existing wood-burning fireplace to see if it will fit. Then, choose the surround/trim/frame so it hides the sides of the fireplace if it's not a perfect fit. Trims for inserts are usually available in a variety of sizes because the size of the frame depends on how big the gap is between the fireplace insert and the firebox opening.

Some typical dimensions for fireplace inserts are:

  • Small: 26" W x 17" H x 14" D (gas) 
  • Medium: 29" W x 20" H x 14" D (gas) 
  • Large: 32" W x 24" H x 16" D (gas) 

These dimensions are approximate and may vary depending on the model and manufacturer of the fireplace insert. Always read the product specifications and installation instructions before purchasing or installing a fireplace insert.

Image of Modern Flames Redstone 42-Inch Built-in Electric Fireplace Insert

In photo: Modern Flames Redstone 42-Inch Built-in Electric Fireplace Insert (RS-4229)

Gas fireplaces 

When considering a gas fireplace for your home, it's essential to factor in not just the dimensions of the visible unit but also the requirements for installation.

For models like the Empire Boulevard for example, the measurement and installation is quite different. It comes with a standoff, and the wall opening must be larger to accommodate combustion. In such cases, measuring only the visible dimensions won't suffice for a proper fit.

Image of Empire Boulevard 36-Inch/48-Inch Linear Vent-Free Gas Fireplace

In photo: Visible dimensions of Empire Boulevard 36-Inch/48-Inch Linear Vent-Free Gas Fireplace

Actual dimensions of Empire Boulevard Gas Fireplace

In photo: Actual dimensions of Empire Boulevard 36-Inch/48-Inch Linear Vent-Free Gas Fireplace | Image from Installation Manual

Another example is the Firegear Kalea Bay Outdoor Linear Vent Free Gas Fireplace. The entire unit may appear big, as seen in the image below. Yet, only the middle part is visible after installation. To ensure a seamless fit, it's crucial to refer to the product's installation manual and follow the specified guidelines. 

Image of the entire unit of Firegear Kalea Bay Outdoor Linear Vent Free Gas Fireplace

In photo: Entire unit of Firegear Kalea Bay Outdoor Linear Vent Free Gas Fireplace with LED Lights

Image of Firegear Kalea Bay Outdoor Linear Vent Free Gas Fireplace with LED Lights after installation

In photo: Firegear Kalea Bay Outdoor Linear Vent Free Gas Fireplace with LED Lights after installation

Electric fireplaces

Electric fireplaces are a convenient and energy-efficient alternative to traditional wood or gas fireplaces. They can provide warmth and ambiance without the hassle of installation, maintenance, or emissions. They also come in different sizes and styles to suit various preferences and spaces. 

The dimensions of an electric fireplace depend on whether it is a wall-mounted, insert, freestanding, or console model. Here are some general guidelines for choosing the right size electric fireplace for your home.

  • Wall-mounted electric fireplaces are designed to hang on the wall like a picture frame. They are ideal for small spaces or rooms where floor space is limited.

Image of Napoleon Alluravision Deep Built-in /Wall Mounted Electric Fireplace

In photo: Napoleon Alluravision Deep Built-in /Wall Mounted Electric Fireplace

  • Insert electric fireplaces are designed to fit into an existing fireplace opening or a custom-built enclosure. They are ideal for replacing an old or unused fireplace or creating a new focal point in your room.

Image of Litedeer Homes LiteStar Smart Built-In Electric Fireplace Insert with Real Flame Effect

In photo: Litedeer Homes LiteStar Smart Built-In Electric Fireplace Insert with Real Flame Effect

  • Console electric fireplaces are designed to double as entertainment centers or storage units. They are ideal for rooms where you want to combine functionality and style. 

Image of HearthPro Nate Media Console with Electric Fireplace for 45-Inch TV

In photo: HearthPro Nate Media Console with Electric Fireplace for 45-Inch TV

  • Freestanding electric fireplaces are designed to stand on their own on the floor or on a pedestal. They are ideal for rooms where you want to add a cozy touch or move the fireplace around as needed.

Image of Touchstone Forte Elite 40-Inch Freestanding Electric Fireplace with White Mantel (#90000-80052)

In photo: Touchstone Forte Elite 40-Inch Freestanding Electric Fireplace with White Mantel 

When choosing the size of your electric fireplace, you should also consider the heating capacity, the power consumption, and the safety features. You should measure the area where you want to place your fireplace and compare it with the dimensions of the models you are interested in. You should also check recommendations and reviews for more information.

Image of fireplace measurements - electric fireplace

 

Recessed fireplaces

A recessed fireplace is a type of fireplace that is installed into a wall or a cabinet, creating a flush or nearly flush appearance. 

Recessed fireplaces can be electric, gas, or wood-burning, and they offer several advantages over traditional fireplaces, such as saving space, enhancing aesthetics, and improving efficiency. However, recessed fireplaces also have some specific requirements for installation, especially regarding the dimensions of the opening and the clearance from combustible materials. 

The dimensions of a recessed fireplace depend on the model and the fuel type. Take note that the opening in the wall or the cabinet should be slightly larger than the fireplace unit to allow for ventilation and wiring. 

The clearance from combustible materials, such as wood, drywall, or insulation, should be at least 3 inches on the sides and top of the fireplace, and at least 6 inches on the bottom. Some models may require more clearance depending on their heat output and design. It is important to follow the manufacturer's instructions and local building codes when installing a recessed fireplace to ensure safety and performance.

Image of ouchstone Sideline Stainless Steel 50-Inch Recessed Electric Fireplace

In photo: Touchstone Sideline Stainless Steel 50-Inch Recessed Electric Fireplace

2-sided fireplaces

A 2-sided fireplace is a type of fireplace that can be enjoyed from two different rooms or spaces. It creates a visual connection and a cozy atmosphere in both areas. 

The dimensions of a double sided fireplace depend on the design, the fuel type, and the installation requirements. However, some general guidelines are:

  • The width of the fireplace opening should be at least 30 inches for both sides.
  • The height of the fireplace opening should be at least 24 inches for both sides.
  • The depth of the fireplace should be at least 18 inches for both sides.
  • The minimum clearance from combustible materials should be at least 12 inches for the sides and 18 inches for the top and bottom of the fireplace.

These dimensions are based on common standards and may vary depending on the specific model of the fireplace. 

Image of Superior Linear Vent-Free Outdoor Gas Fireplace - Optional See-Through

In photo: Superior Linear Vent-Free Outdoor Gas Fireplace - Optional See-Through

Outdoor fireplaces

If you are planning to build an outdoor fireplace, you need to consider the dimensions of the fireplace and the firebox. The dimensions of the fireplace depend on the style, size, and fuel type of the fireplace. 

Here are some general guidelines for outdoor fireplace dimensions:

  • The height of the outdoor fireplace can range from 4 feet to 15 feet, depending on the design and scale of your yard.  
  • The width of the outdoor fireplace can range from 3 feet to 15 feet, depending on the style and size of the firebox.  
  • The depth of the outdoor fireplace can range from 3 feet to 6 feet, depending on the design and materials of the fireplace.  

The firebox is where the flame burns and should be made of heat-safe materials, such as steel or fire-rated bricks. The firebox opening can have different shapes, such as arch, semi-circle, or rectangle. 

Image of Majestic Lanai Vent-Free Outdoor Natural Gas Fireplace

In photo: Majestic Lanai Vent-Free Outdoor Natural Gas Fireplace

Other measurements to consider

Distance of Electrical Outlets

Are there any electrical outlets situated on the wall where the fireplace will be installed? Take measurements of their positions on the wall and ensure that their placement won't hinder the fireplace installation process.

This becomes especially crucial when purchasing an electric fireplace. Remember, an electric fireplace should always be directly plugged into an outlet, and using an extension cable is a big no-no! 

Also, it's a smart move to have a dedicated outlet for the fireplace to avoid overloading your circuit and tripping it in case of any issues.

Image of Simplifire Traditional Built-in Electric Fireplace Insert

In photo: Simplifire Traditional Built-in Electric Fireplace Insert

Clearance

Considering the immediate surroundings of the fireplace is vital. Measure the distance from the top and both sides of the fireplace to make sure there's enough space to avoid potential fire hazards, such as being too close to flammable materials.

Image of Dimplex Revillusion 30-inch Built-In Electric Firebox

In photo: Dimplex Revillusion 30-inch Built-In Electric Firebox

Frequently Asked Questions

How do I measure for a mantel or surround?

To measure for a mantel or surround, measure the width and height of the fireplace opening and the width of the firebox. Mantel depth can vary based on style and personal preference. Ensure the mantel is proportionate to the fireplace and suits your aesthetic.

How do I measure for a fireplace mantel shelf?

To measure for a mantel shelf, measure the width of the fireplace opening or the wall where you plan to install the mantel. Also, consider the desired height and depth of the mantel shelf. Ensure that it complements the aesthetics of your fireplace.

What should I consider when measuring for a gas log set?

When measuring for a gas log set, measure the width, depth, and height of the firebox, as well as the size of the fireplace opening. Additionally, consider the gas line placement and venting requirements, which may vary depending on the type of gas log set you choose.

Remember that accuracy is crucial when measuring for any fireplace-related components, and it's often wise to consult with a professional or refer to manufacturer guidelines for specific products.

Are there specific measurements I should take when installing a gas fireplace or gas logs?

Yes, when installing a gas fireplace or gas logs, consult the manufacturer's guidelines for precise measurements. As a starting point, it would be great to measure the following:

  • gas line connection point - ensure it aligns with the appliance's requirements
  • gas supply line size
  • capacity needed for the specific unit you're installing

Now that you know how to measure your fireplace correctly, get ready to measure your space and find a fireplace that fits your space and style. 

Check out our collection of fireplaces at Modern Blaze. Shop now.

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