Finding the Proper Fireplace Size and Output

Several tape measures laid out perpendicular onto a white background

So, what do you do now that you’ve decided you want a gas fireplace in a room of your house? (Click here for our products list.) Maybe you’re designing a new home and need to factor in fireplace options, or you are looking to replace or modify an older system and need to know where to start. Either way, while we can’t deal with all the options here in one small blog posting, we can discuss briefly how to know what gas fireplace size to consider. 


In order to get the right fireplace size physically, you’ll need to know the dimensions of your firebox (you can do this in reverse order if you are building new). The shape and size will allow you to eliminate options that will not work and focus on ones that will. (See visual.) So, you’ll measure the height, width, and depth of your firebox and also the flue. Keep in mind that the back of the fire box may be smaller than the front. Just measure both the front dimensions and back and tell your fireplace professional when you talk to them. Fireplace and More Store is happy to come do it. And while we’re here, mightn’t we say that we are, objectively speaking, the best measurers in the Joplin and four state area. While we’re at your home, we can discuss options and other considerations we’ve come to know from many years of experience. 


In order to measure your need with the right fireplace size by output, you’ll need to determine how many BTUs you need. A good formula for figuring out how many BTUs are needed is to take a room’s square footage, multiply it by the ceiling height, and multiply that by your climate Zone number. To figure out what zone you’re in, click here. For the sake of time, let’s pick somewhere off the top of our head - first place that comes to mind - completely random - let’s say...Joplin, Missouri. Joplin happens to be in Zone 3 (for reference, Miami is a 1 and Alaska is a 5, your previous partner’s heart would be a 6.) So a living room in Joplin, MO that is 300sqft. X 8ft. ceilings X Zone 3, would need a fireplace size by output of 7,200 BTUs. 

That is a minimum number and assumes it is the secondary heating source. Considering many variables, a room this size could require a BTU output of over 22,500. Other factors would include:

  • Insulation
  • Location of the fireplace in the house
  • Proximity to the main heat source
  • Ventilation and Circulation types
  • Limitations of your hearth
  • The default temperature of your housemates’ toes
  • Others 

Somewhere between Ebenezer Scrooge’s candle in the middle of the room and a crematory, we’ll help you find the perfect fireplace size by physical space and also fireplace size by output. If by chance you decide to DIY this thing, and you want an actual crematory, be sure to use “crematory” and not “creamery.” Otherwise if you search, “what’s the best creamery for a dead body,”  you’ll get a visit from the FBI and 60 Minutes. See, Fireplace and More Store has your back. 

We have true experts standing ready to match you with the perfect fireplace size and overall set up for your home and goals. Contact us and give us a chance to show you why we’re a growing, thriving business in the four state area, and why we have such great relationships with our customers. Between our knowledge, experience, passion, and options, we make the path to a better home worry free!

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2009 Stephens Blvd.
Joplin, MO 64804

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