Whether you own a bar or have your own at home, choosing the right CO2 tank for your kegerator is vital. The CO2 is one of the most critical components of your home bar setup and is what allows you to pour beer straight from a tap. However, there are many different kegerator sizes which makes it confusing to know what size CO2 tank you need.
For most home kegerators a 5lb CO2 tank is an ideal size. The size of the CO2 tank will not impact the quality or taste of the beer from your kegerator. However, having a larger tank will mean that you don’t have to refill as often, and the more kegs you can go through without running out.
When choosing the right tank for your kegerator, there’s also your budget to consider. Smaller tanks cost less money, but you’ll have to refill them more often. This may or may not be a big deal to you. Either way, this article will look at what size CO2 tank you should have for your kegerator. We’ll also look at the variables involved and how to make the best choice possible.
How Much CO2 Does a Kegerator Need?
The amount of CO2 that your kegerator needs depend on the type of beer you’re pouring and how quickly you want to pour it. The more CO2 you add to a kegerator, the higher operating pressure it will have. This means that more CO2 will combine with your beer and form carbonic acid, which can impact your brew’s flavor and aroma profile.
Most home brewers use a 5lb CO2 tank like this one here on Amazon. It is enough to pour several kegs of beer, but is not too large and can fit either in a kegerator or right next to it.
More CO2 will also create more pressure on the beer coming out of your tap. As a result, it will be more carbonated, bubbly, and heady than you might want. While the type of beer you’re pouring will impact the amount of CO2 your kegerator needs, most breweries and bars recommend a setting of 10-14 psi.
How Many Kegs can a 5lb CO2 Tank Pour?
A 5-lb CO2 tank is packed with pressure, and depending on what it’s set to, you can pour between 15 and 22 corny kegs with a 5-lb CO2 tank. However, there are several different keg sizes, and a corny keg is only one of them. Let’s look at the different types of kegs and how many of them you can pour with a 5-lb CO2 tank.
- Corny Kegs
As mentioned, you can pour between 15 and 22 corny kegs with a 5-lb CO2 tank. Corny kegs are five gallons in size and are the most common keg for home brewing.
- Sixth Barrel
Sixth barrels are slightly larger than corny kegs and are 5.23 gallons big. Sixth barrels get used in homebrewing, microbreweries, and elsewhere. Depending on how high your pressure is set, you can pour between 14 and 21 sixth barrels with a 5-lb CO2 tank.
- Quarter Barrel
Quarter barrels are larger than the first two keg types and are 7.75 gallons in size. These kegs are often too large for home brewing unless you know what kind of beer you like and brew a massive batch. A 5-lb CO2 tank can pour between 10 and 14 quarter barrel kegs depending on your CO2 tank’s pressure setting.
- Half Barrel
A half-barrel is one of the largest kegs used in brewing and is 15.5 gallons in size. This type of keg gets used almost exclusively in bars, breweries, and restaurants that go through large amounts of beer. A 5-lb CO2 tank typically isn’t used with a half-barrel keg because it can only pour 5-7 of them.
How Long Will a 2.5 lb CO2 Tank Last?
If you’re a homebrewer with limited space, there’s a good chance that you have a 2.5-lb CO2 tank. As you might have guessed, a 2.5-pound tank will only last half as long as a five-pound one. Here’s a table showing how long a 2.5-pound CO2 tank will last with various keg sizes.
| Keg Size | Number of Kegs |
| 5-gallon Corny Keg | 7 – 11 |
| 5.23-gallon Sixth Barrel | 6 – 11 |
| 7.75-gallon Quarter Barrel | 5 – 7 |
| 15.5-gallon Half Barrel | 2 – 4 |
Once again, how long your 2.5-pound CO2 tank will last depends on where you have the pressure set. Here’s another table with more detailed information about how many kegs different CO2 tanks can pour.
| Keg Size | 5-pound Cylinder | 10-pound Cylinder | 15-pound Cylinder | 20-pound Cylinder |
| 5-gallon | 15-22 | 31-44 | 46-66 | 62-87 |
| 5.23-gallon | 14-21 | 29-42 | 44-63 | 59-83 |
| 7.75-gallon | 10-14 | 20-28 | 30-42 | 40-56 |
| 15.5-gallon | 5-7 | 10-14 | 15-21 | 20-28 |
‘Where Can I Refill My CO2 Tank?
No matter how big your CO2 tank is, you’ll have to refill it at some point. Whether this is because you sprung a leak in your tank or simply go through a ton of beer, it’s inevitable. The good news about CO2 tanks is that they’re refillable, which means you won’t have to splurge on a brand new tank every single time.
CO2 tanks can get refilled at a variety of different places. Welding supply stores, locations that specialize in fire extinguishers, paintball stores, retail compressed gas facilities, and even some local breweries or homebrew shops refill CO2 tanks. Your best bet is to call each of these local facilities to determine which ones will refill your tank and to find the best price.
Some home brew supply shops will simply swap you tanks for around $20. If you don’t have a sentimental attachment to your tank, then this is a great option.
How Do I Know What My CO2 Pressure is Set at?
CO2 tanks are similar to other compressed gas tanks that disperse nitrogen, oxygen, and various other gases. The tanks are made of aluminum to ensure durability and that your CO2 doesn’t get contaminated.
The only way to tell what your pressure is set at is with a CO2 tank pressure regulator. The regulator also keeps the gas inside your tank from overheating and causing an explosion or leak. The regulator is also the only way to get gas out of your CO2 tank in a controlled and usable manner.
The pressure regulator screws onto the top of the CO2 tank and will have either one or two gauges. The primary gauge is what you use to regulate and view your pressure setting. There should be a knob or handle attached to the regulator which allows you to increase or decrease the beer in the kegerator tank pressure.
How to Know When Your Tank is Almost Empty
The second gauge on your CO2 tank will tell you how full it is and whether or not you’re about to run out of gas. The needle on the gauge should be at the spot marked FULL when you get it refilled, and it will slowly make its way toward the EMPTY mark on the gauge as you use it. These gauges are also usually marked with a green section and a red section to indicate full versus empty.
If you don’t have a second gauge that tells you the capacity of the gas inside your tank, there are a few other ways to tell if your tank is almost empty. You may notice that your beer tastes flat or has less carbonation than usual, despite being in the same setting as always.
Another option is to weigh the tank when it’s empty, versus when it’s full. If you continue to weigh the tank as you use it, you’ll have a good idea of when it’s getting close to the empty point based on its physical weight.
Do You Have to Have a CO2 Tank With a Kegerator?
While CO2 tanks cost money and the gas isn’t cheap, your CO2 tank is one of the most important components of a kegerator. Kegerators are stored on the ground, and the keg of beer is placed inside them. The only way that beer at ground level can defy gravity and rise up to the top of the tap is with CO2 gas applying pressure to it.
In addition to propelling beer upward, CO2 also mixes with beer inside a keg to carbonate it. With the right amount of CO2 and a tank, your beer will likely taste flat, flavorless, or watered-down. CO2 tanks take maintenance and upkeep, but they’re vital to the operation of your kegerator.
