How to Pick the Right Size Fireplace

The right size fireplace has two separate measurements: the width of the fire for your wall and the heat rating for your room. Choose the width for the space you have. Use the maker’s rating to choose the heat your room needs. For help with the other choices, start with our fireplace buying guide.

Two sizes: the width for the wall and the heat for the room

The glass or opening forms the viewing area you see. The heat output is the warmth you feel, listed in BTU per hour, a measure of heat, or as the square feet the maker rates it for. Width and heat do not always rise together, so choose each separately.

Every unit we sell publishes exact framing dimensions and clearances in its manual. Those measurements rule the installation.

How to measure the wall for the right size fireplace

Measure the wall’s width and the ceiling height. Leave space beside the fire for the surround. Allow room above for a mantel or TV.

A traditional gas box of 32 to 42 inches suits most living rooms. Go bigger only when the wall and viewing distance support it. Choose a linear fireplace by the length of the wall it sits in. Our fireplace ideas for every space can help you consider the design.

Gas fireplace sizes

Direct vent means a sealed unit that vents through a wall. Traditional direct vent gas fireplaces range from 30 to 48 inches wide. The Napoleon Ascent comes in 30, 36, 42 and 46 inches. The Empire Tahoe comes in 32, 36, 42 and 48 inches. The Superior DRT series offers 35, 40 and 45 inches.

Our linear fireplaces include the Empire Boulevard in 36, 48, 60 and 72 inches, the Superior DRL series in 48, 60, 72 and 84 inches, and the Napoleon Vector in 38, 50, 62 and 74 inches.

The Napoleon Ascent 30 gives 15,000 BTU, enough to take the chill off a small room. Most living room units give 25,000 to 40,000 BTU. The Napoleon High Definition 81 reaches about 60,000 BTU.

The Napoleon Vector 50 gives up to 36,000 BTU with glass about 53 inches wide and 19 inches tall. A see-through unit shares its heat between two rooms.

Electric fireplace sizes

On a normal wall outlet, an electric fireplace gives about 5,000 BTU. Makers rate that for up to 400 square feet, so think of it as a fire first and a heater second.

Some electric fireplaces give 9,000 to 10,000 BTU when an electrician hardwires them to 240 volts. The Napoleon Elevation X 36 gives 5,000 BTU plugged in or 10,000 hardwired.

Widths range from the 26-inch Napoleon Cineview 26 insert to 120 inches in the Modern Flames Orion Multi and Landscape Pro Multi ranges. The built-in Napoleon Element 42 is 42 inches wide and rated for 400 square feet.

Wood fireplace and wood stove sizes

Use the maker’s floor-area rating for closed wood burning indoor fireplaces and wood stoves. The Osburn 1700 covers 500 to 1,800. The Osburn 2000, Inspire 2000 and Matrix cover 500 to 2,100.

The Osburn 3500 Wood Stove with Blower covers 1,000 to 2,700 square feet with up to 110,000 BTU. The Superior WXS2000 takes 16-inch logs and heats 700 to 1,400 square feet.

For closed fireplaces, the Osburn Stratford II covers 750 to 2,200 square feet. The Osburn Everest III covers 750 to 2,500. The Osburn Horizon Wood Fireplace covers 1,000 to 2,800 with up to 95,000 BTU. The Majestic Pioneer III covers up to 3,000 square feet.

Open wood fireplaces such as the Superior WRT3000, Majestic Biltmore and Empire Blackburn are sized by width, from 36 to 54 inches. An open fire is for looks more than heat. A closed, EPA certified wood burning fireplace burns cleaner and gives more warmth from the same firewood.

Inserts must fit the opening you have

A fireplace insert must fit the existing firebox, the space where the fire burns. Measure its opening’s width, height and depth before comparing fireplace inserts. Our explanation of what a fireplace insert is provides more background.

The Majestic Ruby gas insert comes in 25, 30 and 35 inches. The Superior DRI2000 comes in 27 and 32 inches. The Empire Innsbrook gives 20,500 BTU in the small size and 28,000 in the large.

The Osburn 2000 wood insert covers 500 to 2,100 square feet. The Osburn 3500 insert covers 1,000 to 2,700. Electric inserts start at 26 inches.

Outdoor fireplace sizes

Size outdoor fireplaces to the seating in front of them. Outdoor gas models run wider and hotter because the air moves.

The Majestic Lanai Outdoor Gas Fireplace comes in 48 or 60 inches with 55,000 to 65,000 BTU. Other outdoor gas fireplaces include the Superior VRE4600 in 36, 48, 60 and 72 inches with 31,000 to 65,000 BTU. We also carry outdoor wood burning fireplaces.

Clearances, hearth and the manual

The manual gives each clearance to anything that can burn and the required mantel or TV height. It also specifies the hearth, the protective surface beneath and in front of the fire. See our fireplace hearth guide for more.

Wood units need a hearth and chimney. Direct vent gas units vent through a wall or roof. Electric units need neither a hearth nor a vent. Local code and the maker’s manual decide installation requirements. A licensed installer connects gas. Our gas fireplace installation guide covers that work.

Questions people ask

What is the best fireplace to buy for my home?

For most homes, a direct vent gas fireplace offers a sealed fire and push-button heat. Choose electric when installation needs to be simple. Choose wood when tending the fire is part of the appeal. The best match depends on the house and your habits.

Can I hang a TV over my fireplace?

Electric fireplaces are built to share a wall with a TV. The Modern Flames and Napoleon three-sided and linear electric models are made for a media wall. Above a gas or wood fireplace, follow the manual’s minimum height for a mantel or TV. That measurement is the rule.

What are the different types of fireplaces available?

Gas choices include direct vent, ventless and B-vent models, on natural gas or propane, plus gas log sets for an open masonry fireplace. Electric choices include wall mounted, built-in and insert models. Wood choices include open fireplaces, closed EPA certified fireplaces and freestanding stoves. Inserts fit an existing firebox. Outdoor units come in gas, wood and electric versions.

Choose the right size fireplace by checking the wall measurements and the maker’s room rating separately. Then confirm the clearances in the manual. Browse our whole fireplace collection, or send us a photo and your wall measurements so we can shortlist units that fit. My Cozy Outdoors sells every fireplace named here as an authorized dealer with the full manufacturer warranty.