Skip to Content

Outdoor Fire Pit BTU Guide

Outdoor Fire Pit BTU Guide

There’s nothing quite like the feeling of sharing a winter night with friends around a fire pit.

The warm atmosphere of camaraderie accented by the flickering flames of the fire pit leads to unforgettable experiences. That said, when it comes to something like installing and maintaining a fire pit in your home, you naturally want to make sure your fire pit is up for the task at hand.

With that in mind, this outdoor fire pit BTU guide can help you ensure that everything is ready to go before you set yours ablaze.

What is a BTU?

For those not in the know, BTU stands for British Thermal Unit. This is defined as the amount of thermal energy needed to raise the temperature of a pound of water by a single degree Fahrenheit at sea level.

That sounds complicated, but what it boils down to (…get it?) is BTUs being a way of measuring how much thermal energy something emits. This measurement can be useful when it comes to things like fire pits or barbecues.

These products don’t just emit heat for show, after all — they need to emit enough to efficiently warm yourself, your friends, or the food you’re cooking.

On the other hand, you don’t want to feel like you’re being roasted yourself!

This is why it’s so important to pay close attention to how many BTUs a fire pit has. That way, you and your friends can feel warm without feeling like you’re being sautéed.

How many BTUs does your outdoor hardware have? For fire pits powered by propane and natural gas, chances are the BTU output will be somewhere in the tens of thousands.

BTU relation to flame height

Folks often wonder if BTUs directly impact the height of your fire pit flames.

The answer is yes — the higher the BTUs, the higher you can expect the flames in your fire pit to rise. That being said, flame height is also governed by many other factors. As such, while BTU tends to be proportional to your flame height, it is not a one-to-one match.

How many BTUs does your fire pit need?

Naturally, this is a somewhat subjective question. After all, everyone has their own heating preferences, and feels “warm” at different temperatures.

In addition, there are many factors which can impact how warm you feel around a fire pit, including (but not limited to):

  • The proximity to you and your guests
  • Whether they are used in an open area or a more enclosed space
  • Your regional climate
  • How windy it is outside
  • What type of fire pit (here’s a comparison of 3 different kinds)

In fact, the only reliable way to determine your BTU needs is to measure the temperature of the flame using a thermometer like this one and ask yourself how you feel. It’s not subjective, but that doesn’t mean we can’t apply a bit of science to it!

With all of that being said, a standard propane outdoor fire pit should feature somewhere between 40,000 and 150,000 BTUs worth of thermal energy. If this seems like a wide range, it’s because it is!

Which fuel is right for your BTU needs?

Any fire needs fuel, and your fire pit is no exception. In order to get the most out of it, you will want to make sure to use fuel which is highly efficient in the way it burns and gives off heat.


Wood-burning fires are a popular choice here. There are many reasons for this. For one thing, there’s just something nice and homey about a wood fire. For another reason, wood is a cheap natural resource, and burns reasonably efficiently. It can even burn so hot that the fire pit doesn’t produce much ambient smoke, creating smokeless fire pits.

You can also adjust the BTU output by simply adding to or reducing the amount of fuel!

However, wood burning fire pits have fairly intensive upkeep and wood can be difficult to source and expensive to keep buying!

Propane and Natural Gas

Gas fire pits are a natural choice for those that require easy clean-up and don’t want to spend an arm and a leg on fuel. Although the fire pits themselves can be more expensive, they’re less work in the long run. They’ll likely save you money if you plan on using your fire pit often!


If you are looking for lower BTUs, bio-ethanol fuels, in both liquid as well as gel form, can burn a lot less intensely than the alternatives.

The same holds true for electric-powered heaters, although this will obviously depend in part on the power of your heater.

Safely positioning your fire pit

Regardless of how many BTUs your fire pit has (or what kind of fuel it burns), you’ll want to make sure that it’s safely placed. This naturally depends on several factors, most importantly the size of your outdoor area.

Your fire pit should always be placed in an open area free from any additional structures or stray debris. The last thing you want is an ember or flickering flame catching something else on fire and causing a catastrophe.

Make sure that your fire pit sits at least 15 feet or more away from any structures. If your fire pitis on the higher range of BTU output, this should be even further.

There is a reason why fire pits tend to feature sturdy cast iron shells. You don’t need cast iron furniture. However, it helps if any of the furnishings you have close by are made from a fire-resistant material.

This site uses Akismet to reduce spam. Learn how your comment data is processed. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of, Inc., or its affiliates.