Grilling Tips & Hacks: How Long Does a Small Propane Tank Last?

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A compact portable gas grill, the like of Weber Q1200, is the best to cook your meals on the go. You can even enjoy your BBQ out there in the sea while cruising with friends. But then, how long does a small propane tank last? Will it be enough to grill short ribs until tender?

When grilling at home, the gas tank drying up is usually not a concern for many of us. But when you decide to take your appliance on the go, it can be frustrating and disappointing. The situation will be worse if the gas tank runs empty before you prepared the dinner and you’re in the middle of nowhere.

In this guide, I’m going to share everything you should know about how long a small propane tank last to cook. But before we come to that…

Which Exactly is A Small Propane Tank For Grill?

As you know by now, there are many types of gas grills for our (I mean us BBQ lovers) craft. I personally place models like the Weber Genesis II E-315 and E-335 in the full-range category, as you also get complete capabilities, including the option to handle large meals.

However, these full-range grills are bulky and nearly impossible to use on the go. Yes, I’ve seen some friends with large RVs take them. But a compact model like the Q1200 or even upgrades Weber Q2000 and Q2200 are usually more convenient.

Like any other appliances, compact grills still need fuel to burn. Many of the options I’ve been able to go through usually operate on liquid propane, albeit you could convert to natural gas.

Liquid propane is a more convenient fuel with these cookers, though. And what makes it convenient are the small tanks since they are also portable.

How Long Does a Small Propane Tank Last
Grilling recipe

Usually, the lads at gas refill centers often identify a small propane tank as anything below the standard 20lb can. Thus, we’re looking at propane can sizes 11lb, 5lb, or 1lb.

In my opinion (I’m sure it may differ from yours), the 11lb and 5lb cans are still a bit large. It’s not something you can attach on your compact grill and do a sprint in the event of a bear attack.

The 1lb (or 16oz) propane can is what qualifies to me as “small”, as the girl can lift the whole set without a hassle. It (a full 1lb propane tank) only weighs about 29 ounces and when screwed on the cooker, it is still effortless to lift.

How Much Gas do You Have in the Small Propane Tank?

It’s pretty obvious the 1lb (16oz) propane tank also packs 1lb of liquid gas, right? Wrooong! Many people will just assume this since it’s already on the attached sticker, and so would I if I didn’t know better. But the exact amount of gas available is usually a few ounces less. Why so?

Like any gas or even liquid, propane will expand when heated. And for this reason, the holding tanks usually come filled at up to 80%, then the remaining space will be for when expansion happens.

If you have the 30lb propane tank, this would mean you’ll get about 24lb fuel, whereas our 1lb small can is 0.8lb. Otherwise, when the gas expands and has no room to go, it could start leaking from the valves or anywhere it finds space. In extreme this could lead to an explosion or a disastrous inferno.

When we now come to calculate your available propane gas in gallons, it’ll vary with the metrics you’re using.  

For me, I’m going to use the metrics rule from at “1-gallon propane is equal to 4.25lb”. And when we calculate the 1lb tank (at 0.8lb gas capacity), we get roughly 0.1882 gallons of propane.

In case you’re wondering, I’ve done this conversion so we can use it to calculate the gas usage formula in the next segment. Then we can estimate how long small propane tank last in continuous grilling.

Of course, the conversion formula could work while still in pounds, but I kind of feel gallons is a little more accurate. The standard BTU content formula of propane is also in gallons, where 1 gallon equals 91,500 BTUs.

Now, this brings us to our theme question…

How Long Does a Small Propane Tank Last?

When talking about grills and cookers, we often use BTU/ hour to calculate the total heat output. Then to know how long does a small propane tank last, the rule of thumb is to divide the total energy (BTUs) by appliance output.

For instance, our reference Weber Q1200 has a maximum output (amount of heat on full throttle) of 8,500 BTU/ hour. I fancy playing with numbers and this would mean:

Our small (1lb) propane tank contains roughly 0.1882 gallons of gas, remember? If we convert to BTUs, this will be about 17220 BTUs (0.1882 x 91,500).

You’ll notice some people say the 1lb propane gas is 22,000 BTUs, which is somewhat correct. The difference is that they calculated with a 100% full tank, instead of the 80% rule.

Back to our Weber Q1200, the full throttle will suck up approximately 8,500 BTUs in one hour. If we divide the tank capacity (17,220 BTUs) by this number (8,500 BTUs), it leaves us with approximately 2 hours.

This would mean the small propane tank can last up to four hours when cooking at medium heat. But in an actual BBQ test, the gas lasted exactly 10 minutes to 4 hours (ha-ha, I mean 3 hours 50 minutes).

If you’re grilling ribs, which is best at low-and-slow temp, this would also mean the small propane tank can go up to six hours.


Apart from the heat setting level, the temperature in your area does affect how long your propane tank last. It’s most noticeable during winter and rainy seasons when the air is cold since the cookbox takes longer to heat up. And when the grill takes longer to heat up, it will be working harder, which ends up using more fuel.

Frequently Asked Questions:

What are the most common propane tank sizes

In a nutshell, you can equip your property with up to a 2000lb horizontal tank. But the most common propane tank sizes for backyard BBQs are 20lb and 30lb. The 1lb propane tank is the smallest, but you could also get sizes 5lb and 11lb.

What are some common uses for propane?

The common uses for propane are cooking on the grill or cooker, lighting a lantern, plus heating the furnace and portable heater.

How Do I Know If My Propane Tank Is Empty?

The easiest way to know a propane tank is empty is to check the gauge meter (if available). If your tank doesn’t have the gauge, you can weigh it and subtract the results against the tare weight (of TW which is the weight of the gas tank when empty). You could also use the warm water trick and feel where the tank is cold.

How Long Does a 1lb Propane Tank Last?

How long a 1lb propane tank last depends on the amount of gas available and your cooking setting. If you have a full tank and grill at medium heat, you can have nearly four hours of continuous cooking.

How Do You Refill a 1 Pound Propane Tank?

Many sellers don’t recommend it, but you can refill a 1-pound propane tank at home or even during your road trip. You just need to hook up the dedicated refill adapter on the large tank, then:
Screw on the small propane tank
Turn on the gas flow valve from the supply (large tank)
Wait until the small tank refills. You can listen until the “hissing” stops
Once the tank gets enough air, turn off the valve from the supply tank
Finally, disconnect the tanks from the refill adapter

Cooking at Low Heat Doesn’t Exactly Save Your Gas :

If you plan on taking your BBQ on the go this year, that’s everything you need to know on how long a small propane tank last when full. It’s a pretty easy trick as you just need to calculate the BTUs and take them out with the output of your grill/ cooker.

As I’ve mentioned, grilling at a high heat level does suck up your propane fast. But at the same time, do know cooking at low temp doesn’t exactly save on your gas.

When at low heat, your food tends to take longer to cook. And this is to say it will stay longer to achieve that desired doneness.

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