When we go camping or over to my mom’s with her gas fire pit, I’m often asked:
How much gas does a fire pit use?
I knew there was no specific answer, but I also didn’t know how to figure it out.
So I researched, and here’s what I came up with.
A fire pit burns through the gas roughly equal to its BTU output. If a fire pit puts out heat at 40,000 BTUs, it’ll use up that much BTU from a propane tank. One gallon of propane is equal to roughly 25,000 BTUs.
If that math sounds tricky, don’t worry! We’ll walk you through some more details in the rest of this article.
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Table: How Much Propane Does A Fire Pit Use?
This chart gives you a great idea of how long a fire pit lasts on different sizes of propane tanks.
| BTU Output Of The Fire Pit | 1 Pound Propane Tank (25,000 BTU) | 5 Pound Propane Tank (125,000 BTU) | 20 Pound Propane Tank (450,000) |
|---|---|---|---|
| 30,000 BTU | 1 hour | 4.20 hours | 15 hours |
| 40,000 BTU | 0.625 hours | 3.125 hours | 11.25 hours |
| 50,000 BTU | 0.5 hours | 2.5 hours | 9 hours |
| 65,000 BTU | 0.48 hours | 1.9 hours | 6.9 hours |
| 75,000 BTU | 0.33 hours | 1.67 hours | 6 hours |
| 100,000 BTU | 0.25 hours | 1.25 hours | 4.5 hours |
A fire pit burns through its BTU output per hour, so it needs at least that much in a propane tank to run well.
As propane gets lower, it tends not to run as hot too.
Some simple math will work to figure out exactly how much a fire pit needs to run per hour.
1 gallon of propane equals roughly 25,000 BTU.
So divide the BTU of the fire pit by 25,000 to get how much it needs to run per hour.
For example, take the standard 40,000 BTU fire pit.
To figure out what it needs, do the math problem:
40,000 BTU fire pit / 25,000 BTU per gallon of propane = 1.6 gallons of propane needed.
If you’re going camping and looking for a quality portable propane fire pit, check out our picks for the best portable gas fire pits for various situations.
How Long Does A Propane Fire Pit Last?
A propane fire pit will last around one hour per gallon of propane available when producing 30,000 BTU of energy. For more specific numbers, divide each gallon of propane at 25,000 BTU each by the overall productivity of the fire pit to get the rough number of hours.
As far as durability over the years on your firepit go, it depends on how much you clean and how long you run it.
Theoretically, a propane campfire could last with repeated use for years.
The keys to maintenance are:
- Clean the burners and debris off the fire pit
- Don’t use the burners for many hours in a row
- Make sure the regulator is in good working order
I’ve known people who (whether it’s their fault or not) only get to use them for a year before they break.
In most short cases like this, something on the manufacturer’s end failed.
If it breaks down after a couple of years, the user is doing or failing to do something.
My mom has a quality gas fire pit for her deck, and it’s been around for 15 years at this point.
The only issue was when we kept it on for 12 hours and just changed out the propane tank when it was emptied.
The heat did nothing to harm the actual burners or fire-producing parts, but it did crack the decorative inlays.
We replaced those and then kept using them.
I’ve had my smaller portable gas fire pit for camping for around 5 years with no issues, but I do make sure it’s clean and free of debris after use.
How Long Does A 1.5 lb Propane Tank Last On A Fire Pit?
The average 1.5 lb propane tank lasts around one hour on a fire pit. The propane tank will produce around 35,000 BTU which falls into the range of BTU production of most fire pits. It’ll burn through this in around an hour.
One-pound propane tanks are great and easy to carry, but on something that burns a bit more, it won’t last long.
These little guys are meant for helping on a quick grill, lantern, or portable blow torch, and other such things.
It’s perfect for roasting marshmallows or cooking a quick meal.
Learn about the safety of roasting marshmallows over a gas fire pit in our article at the link.
In general, I’d suggest keeping at least a 5-pounder around if you don’t want to move around a 20-pound one.
How Long Does A 20-Pound Propane Tank Last On A Fire Pit?
A 20-pound propane tank will last around 8-10 hours on a fire pit. Most propane fire pits burn 40,000 BTUs per hour (or higher), and a 20-pound tank carries a little under 450,000 resulting in around a 10-hour window.
If your fire pit has the power to control the intensity of the burning, turn down the heat when you don’t need it up as much, and it’ll help the tank last longer.
Can I Use A 15 Lb Propane Tank Instead Of 20 For Fire Pit?
Using a 15lb propane tank (or any size) instead of a 20lb tank for a fire pit is perfectly fine. The size has little to do with any functionality or pressure. Size correlates only to the amount of propane and length of time the fire pit will burn.
The biggest issue with using different sized propane tanks is that you need to make sure whatever tank you use connects securely to the hose or fire pit with no leaks.
These connectors are all pretty universal.
A portable fire pit or gas grill for camping will come with a hose to use with 5-pounders or above, and then the hose will also attach to a 1 or 1.5-pound tank.
Or the hose will remove completely and let the tank screw directly in.
Take a look at what tank you have, and you may be surprised to realize they all connect well.
Warning: After you attach your tank, wait a minute and listen for leaking sounds. Also, sniff the air after a few minutes to see if you still smell the propane odor.
If you notice either of these, disconnect the propane and let the area air out for 15 minutes.
If you’re on the fence for these pits, check out the pros and cons of propane fire pits.