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Learn How to Check Propane Tank Levels on Gas Grills

Picture this: You’ve invited friends over for a barbecue, you have your meat marinating, and you’re ready to fire up the grill for a great day.

But when you go to light your grill, the flames sputter, flicker out, and then — nothing. You’re out of gas.

If you’ve been in this situation before, you know how much of a bummer it can be. But it doesn’t have to be!

In this guide, we’re going to give you all of the tips and tricks you need to check your propane tank level with confidence, so you never run into a situation like that again. 

We’ll walk you through how to check your tank level with common techniques like the hot water test, weighing it on a bathroom scale, or doing a little math.

We’ll wrap it all up with some FAQs, and get you well on your way to mastering the art of checking your propane tank’s fuel level.

How to Check Your Gas Grill Propane Tank Level

The Warm Water, Cool Hand Method | Using a Gauge | Using a Scale | Using Simple Math

Checking your gas grill’s propane tank doesn’t require any rocket science.

In fact, there are a few easy ways you can make sure you have enough fuel before you fire up the grill for your next cookout.

Below, I’ll provide you with some simple but effective methods to gauge the remaining propane in your gas grill tank so your grilling sessions can go on uninterrupted.

The Warm Water, Cool Hand Method

One of the most popular ways to check your propane tank’s level is with water.

Let your tap run until the water is hot, then fill a cup with the hot water and head out to your grill.

Next, pour that water down the side of your propane tank. Then, run your hand down the side of the tank and feel for where the tank starts to cool down.

The spot where your tank feels cool is where your propane level is — if that spot is near the top, you’re good to go, but if it’s toward the bottom, it’s time for a trip to the hardware store or gas station.

This method works because liquid propane is cool, and the warmth of the water on the outside of the tank makes the temperature difference between the propane and the empty part of the tank much more noticeable.

Is this the most accurate method in the world? Just like the method of holding your hand over the grill to gauge its temperature, not really. But it will give you a general idea of how much fuel you have left before you need a refill.

Using a Gauge to Check Your Propane Tank Level

Most propane tanks don’t come with a gauge on them to help you measure the gas level as your car does.

But if you want a truly accurate reading, without the guesswork, there are specific propane gauges you can pick up from just about any hardware store!

There are a few different types of these available, but the ones we’ll take a look at today rely on pressure to give you a precise reading.

How Does a Propane Gauge Work

An inline propane pressure gauge first needs to be installed between your grill’s gas line and the propane tank’s cutoff valve, allowing it to measure the pressure coming directly from the tank. Think of it like the gauge you use to measure the air left in your car’s tires!

These gauges typically feature a numbered gauge that goes from 5% to 95% and will tell you the percentage of propane left in your tank instead of the number of gallons left. 

On the gauge’s dial, you’ll usually also find color codes in green, yellow, and red that can tell you at first glance whether you have plenty of gas left, will need to refill soon, or are dangerously low. Think of it like a stop light: if it’s green, you’re good to go, but if it’s red, stop what you’re doing to refill the tank. 

If your gauge doesn’t read 95% right away, don’t worry! Tanks are usually only filled about 80% of the way, so there’s room for the gas to expand. If your tank is full, it will usually only read about 80%.

If you ever see your gauge dip below 20%, that’s the time to refill or replace your tank.

Using a Scale to Weigh Your Propane Tank

You can also check the level of your propane tank with a scale. There are a few different options available out there if you’d like to get a dedicated propane scale.

Analog propane scales work a lot like the luggage scales you may use before a big vacation — simply hook the tank on the handle, and lift it up to get your reading.

Digital propane scales are also available and sit below the propane tank to constantly weigh it and provide a digital readout of the remaining gas level and cook time.

Don’t feel like springing for a new scale? No worries! A simple home bathroom scale can work just fine.

To check your propane tank by weight, first check its handle for the TW, or tare weight. This number refers to how much the tank will weigh when it’s completely empty. Your run-of-the-mill propane tank will usually weigh around 17 pounds when empty, and hold 20 pounds of propane.

Once you know the tare weight, disconnect your tank and place it on your scale. Take the total weight and subtract the tare weight to figure out how much gas you have remaining.

For example, if your tank has a tare weight of 17 pounds and your tank measured at 27 pounds, you have 10 pounds, or half a tank, of propane gas left.

Check Your Propane Tank With Simple Math

If you feel like breaking out your math skills before your next barbecue, you can check your propane tank’s level with some basic math.

This method works best for smaller tanks, like those used for portable grills or camping appliances, but it can give you an accurate reading for any tank if you’re willing to do the calculations.

First, take the weight of the total amount of propane your tank can hold (typically 20 pounds) and divide that by 4.2 to convert the weight to gallons.

Next, figure out how many BTUs per hour your grill typically consumes. You typically can find this either marked on the side of the grill or in your user’s manual.

Then, find the maximum BTUs per hour your grill would consume if all of the burners were turned to high — this is the number we’ll be using in our equations.

One gallon of propane gas produces around 92,000 BTUs, so if you have a typical 20-pound tank, that’s 4.76 gallons or 438,000 total BTUs that your tank can produce when full.

If your grill’s maximum BTUs per hour is 30,000, divide 438,000 by 30,000 to find the total amount of cooking time your tank can provide. In this instance, that equation gives us 14.6, which means your tank can handle between 14 and 15 hours of cooking time.

That answer is, of course, the total cooking time your tank can provide if your grill is on full blast. If you only plan on cooking on half heat, multiply 14.6 by two — at that level, your tank can provide 29.2 hours of cooking time.

How Do I Know if My Propane Tank Is Low?

Outside of the methods we detailed above, you can also get a sense of when your tank is low by simply picking it up.

First, pick it up when it’s full to get an idea of how the tank feels at its full weight. When you pick it up later, if it’s much easier to lift than it was totally full, that’s a good sign that you’re running low on propane.

When your propane starts running low, you may also notice that your grill’s flames don’t burn as high as they did when the tank was full. If you notice a drop in your grill’s flames or overall performance, it’s likely time for a refill.

What Should You Do With an Empty Propane Tank?

When your propane tank is empty, take it to a filling station or retailer like a hardware or grocery store to exchange it for a full tank. This typically gives you a discount on your new tank.

You can also take your empty tank to a filling station that specializes in propane and have it refilled. You may have to do a quick internet search to find one in your area.

Whatever you do, do not throw them away! Propane tanks are incredibly easy to refill and recycle, and you typically get a discount for doing so, so hang on to that tank.

How Do You Know if Your Propane Tank Is Expired?

You typically won’t have to worry about an expired propane tank, since these can last between 10 to 12 years and we hope you grill more often than that.

If you have an older tank that you’re unsure about, take a look on the top near the handle to find where its manufacturing date is stamped — if it’s more than 12 years old, it’s likely expired.

Here is a good article: How to Properly Dispose of Old Propane Tanks

Gas Grill Propane Tank Frequently Asked Questions (FAQs)

Understanding how much fuel is left in a propane tank can be the difference between a great day of grilling and a bust, so if you have any lingering questions, keep reading!

Below you’ll get answers to some of the most frequently asked questions about gas grill propane tanks.

If you don’t find what you’re looking for, leave your question in the comments below or send me an email and I will get back to you.

Who knows, I might even add your question to this guide.

For a more in-depth frequently asked question guide, you check out this article: The Ultimate Gas Grill FAQ

How Long Does a Propane Tank Last?

The lifespan of a gas grill propane tank is typically 12 years from the manufacture date, after which it needs requalification or replacement. It’s important to inspect your tanks regularly for signs of wear, rust, or damage and make sure they meet safety standards before refilling.

How Much Cook Time Can I Get From a 20LB Propane Tank?

A 20-lb propane tank can provide approximately 18-20 hours of cook time on a standard grill, depending on the grill’s BTU rating and the intensity of use. If you have a large grill, which requires more gas to heat, it may only give you 10 hours of cooking time.

How Much Does a 20 LB Propane Tank Weigh When Full?

A 20-lb propane tank, when full, weighs about 37-38 pounds since it weighs 17 pounds when empty. This includes the weight of the tank itself (around 17-18 pounds) and the 20 pounds of propane it contains. Always handle propane tanks with care.

How Do I Know if My 20LB Propane Tank Is Expired?

You can check the manufacturing date stamped on the tank collar to see if it is expired. A 20lb propane tank typically has a lifespan of 12 years from this date. After that, it requires recertification every 5 years. Ensure you inspect or replace expired tanks for safety.

How Do I Dispose of an Expired Propane Tank?

To dispose of an expired propane tank, first, make sure it’s empty. Then, take it to a local hazardous waste collection site, recycling center, or propane supplier. Some suppliers offer exchange programs. Never throw an old propane tank in regular trash or recycling bins due to potential safety hazards.

Final Thoughts on Our How to Check Propane Tank Levels on Gas Grills Guide

So the next time you’re ready to head out to your patio for a day of grilling, remember, to check your propane tank before you do.

Checking your propane tank’s level may seem complicated, but it doesn’t have to be! With a little hot water, math, or weighing, you’ll soon be on your way to a fantastic outdoor cooking experience — or to the hardware store to exchange your empty tank for a full one.

Whether you opt for the hot water trick, the bathroom scale technique, or invest in a dedicated propane gauge, understanding how to check your propane tank level is a smart skill to have that will help boost your cooking confidence and elevate your grilling abilities.

If you have any questions about checking your propane tank’s fuel level, let us know in the comment or over email and we’ll do what we can to get you an answer!


Pat G.

Next Steps:

Step by Step Instructions on How to Light a Gas Grill

How to Light a Gas Grill: Beginner Tips

What Is a Gas Grill Regulator

Troubleshooting Gas Grill Regulator Problems

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How to Manually Light a Gas Grill Safely

DisclosureAt The Grilling Life, I am committed to researching and writing thoughtful, informative and editorially independent reviews of the best products for your outdoor cooking needs.  If you like what I do, you can support me through my chosen links, which earn me a commission.  This allows me to continue sharing with you my love for all things barbecue.  Your support is truly appreciated.

Patrick Ginise

A backyard warrior, certified carnivore, lover of good whiskey, grill master and I’m Living The Grilling Life!

I have a passion for cooking with live fire and smoke, no matter the weather. I’m a real person just like you, who loves outdoor cooking and BBQ. Food, fun, and time spent with family and friends are what it’s all about! It is my mission to take my passion and knowledge for outdoor cooking and all things BBQ and share this expertise in techniques and grilling equipment with you. In other words, Living The Grilling Life!

I have personally tested over 150+ Grills and Smokers and hundreds of grilling thermometers, temperature controllers, grill brushes, grilling tools, fire starters, and other BBQ products.