How To Tell How Much Propane Is Left In Your Tank

Ossiana Tepfenhart
by Ossiana Tepfenhart

Picture this. You’re at a BBQ. You are grilling with propane, but you don’t remember the last time you paid Hank Hill a call. You know you want to get those burgers sizzling, but you aren’t too sure how much gas is left in your tank. What can you do? How can you tell how much propane is left in your tank, anyway?

There are several ways to figure out how much propane is left in your tank. You can install an external gauge that will give you an exact reading, dip the tank in warm water to see where the “cold spot” is, or weigh the tank. When determining the amount of gas left in your tank, it’s important to make sure that the tank is safe to use.

Figuring out how much propane you have left can help you figure out whether you need to take a trip to your local store, and also can help you save money. However, it’s important to know what you’re getting out of your tank and to know if your tank is safe to use. This article will tell you how to figure things out.

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How To Tell How Much Propane Is Left In Your Tank

There are three common ways to know how much propane you still have left. They are as follows:

  • Weigh It
  • Installing a Gauge
  • Use The Warm Water Method

In order to understand what you need to do, how it helps you gauge your propane levels, and how to use each method to its most accurate extent, we decided to make this handy guide on each one.

Using The Weight Method

The fastest way to figure out how much propane you have in your tank is to take the tank out and weigh it. To figure out how much propane you have left in your tank, you will need to read the two measurements on the side of your tank: the Water Capacity (“WC”) and the Tare Weight (“TW”). From there, you can accurately read how much gas you have left.

  • To know the amount of propane that the tank holds when it’s full, multiply the WC by .42. This gives you the weight of the gas, at maximum, excluding tank weight.
  • The TW is the weight of the tank when it’s completely empty. If your tank weighs the same as the tare weight, it’s completely spent.
  • To find out how much propane you have left, weigh your tank then subtract the tare weight. You can then divide by .42 if you need to know exactly how many pounds of gas you have left.

What Is The Average Weight Of A Propane Tank?

On average, most home propane tanks will have a tare weight of 17 pounds. They also will hold a maximum of 20 pounds of gas, which means that the total weight of an average, full propane tank will be 37 pounds.

Do You Need To Buy A Propane Tank Scale To Weigh Your Tank?

There are such things as propane tank scales, and they’re regularly used in propane stores. Though these scales can give you an accurate reading, there’s no need to buy one. As long as you have a scale that you can use to weigh the tank, you should be good to go.

How Much Does An Empty Propane Tank Weigh?

An empty propane tank will weigh the exact same as the tare weight written across it. So, on average, this means it’ll weigh about 17 pounds. If you have a larger tank, it’ll weigh the same as the number written on the side of the propane tank next to “TW.”

How Much Does A Gallon Of Propane Weigh?

Curious about the exact amount of propane you could potentially have in that tank? Weighing it out is a smart choice here. Propane weighs 4.24 pounds per gallon. So, if you have around 8 and a half pounds of extra weight above the tare weight, you have about two gallons of propane that you can use.

Installing A Gauge

If you need to have an exact measure on your propane’s gas tank levels, the easiest way to make sure you get it right is to install a gauge on the side of the tank. A typical propane gauge can be found on Amazon for around $17 and will give you a fairly accurate reading when it comes to the amount of gas that’s left in your tank.

Gauges are handy to have because they’re reliable, reusable, and easy to install. If you don’t want to do math or weigh out your propane tank, these can be a quick and easy way to read your gas levels.

Using The Warm Water Method

If you don’t have a scale or a gauge nearby, there’s still a way you can find out how much gas you have left in that tank. Here’s how to use the warm water method.

  • Grab a tub and fill it with warm water. This should be large enough to place your propane tank in.
  • Disconnect the tank and pour hot water down its side. It should be warm to hot to the touch.
  • Place your hand on the wet side of the tank, and search around for the highest level that you can feel a “cold spot.” This is the level of gas that your propane tank has been filled up to. Since propane is kept cooler, the temperature difference gives it away.

This method is ideal for moments where you just need a general idea of where you are in terms of fuel storage. For example, the warm water method can work well if you just need to know if you have enough propane for a cookout. It will not work well if you’re trying to ration things out to a precise level.

Which Method Is The Most Accurate Way To Figure Out How Much Propane You Have Left?

Generally speaking, using a gauge or weighing your tank to calculate how much propane is left will be the most accurate methods you can make. If you are not used to using a gauge, or don’t want to weigh your propane tank, the warm water method can work. However, it’s not very accurate and can be difficult to work with depending on the weather.

It’s important to remember that gauges will only tell you a general amount of gas that you have, based on the density of the gas inside the tank. That being said, having a gauge will still be more reliable than using the water method. If you need to get a highly accurate reading on propane levels, weighing it is your only option.

Important Rules Of Thumb To Know

There are several things that you need to know if you’re going to try to use a propane tank that you’ve already partially spent. To make sure that we get everything up front, we’re going to break down the rules by category.

Should You Even Use That Propane Tank?

Just because a propane tank has gas in it doesn’t mean it should be used. Propane tanks that show serious signs of safety problems can become a major fire hazard, and can even explode if hooked up to a grill. If you notice any of the following warning signs, it’s best to refrain from using it at all:

  • There are huge rust spots all over the tank. A little rust isn’t that bad a thing, and shouldn’t be cause for worry. However, when rust starts to take a large part of the tank’s overall appearance or goes so far as to corrode the tank’s edges, it’s no longer safe to use. There’s a chance that propane could leak out through the rusted parts!
  • You notice large dents in the tank. Dented tanks should be cause for alarm, primarily because it can impact the way propane is being stored inside. If you notice major dents and your tank is mostly full, you probably shouldn’t use it. Or, better still, just don’t use a dented tank.
  • There are signs of the propane tank being tampered with. Does the tap look like it’s been hit with a crowbar, or like someone tried to “peel” it open? Do you notice serious signs of your tank being messed with? If so, that propane tank is probably not safe to use, even if it’s full. Should you find a tank that’s been visibly tampered with, return it to the store and explain what happened. They will be able to help you dispose of it properly.
  • You smell propane gas in the air. This might be okay if you actively are trying to release the gas, but it’s not okay if you’re about to light up your grill. This suggests that there is a leak in your tank, which could lead to serious explosions if a match is lit nearby.

When in doubt, it’s better to just assume that the tank is unsafe to use and should be properly disposed of. After all, it’s better to be safe than sorry.

How To Dispose Of A Bad Propane Tank

The best way to dispose of a bad propane tank is to contact your local hazardous material group, or to reach out to the propane tank’s manufacturer. Most manufacturers offer free disposal services as long as you are disposing of a typical barbecue propane tank or something of comparable size.

One thing you don’t want to do is try to cut the tank open. You also shouldn’t try to drop it off at a recycling center. Damaging the tank can be dangerous, and most recycling centers don’t allow propane tanks to be accepted on their properties. That said, a quick call ahead of time can help you determine if your local center is the exception to the rule.

How Can You Tell If The Propane Tank Is Empty?

Sometimes, it just doesn’t make much sense to go through all the motions of buying a gauge or dropping a tank in hot water. Sometimes, you just need to know if there is any juice left in your gear. Wondering how to figure out if the tank is empty? Look for these signs below.

  • The tank weighs the same as the tare weight. Sometimes you can just “feel it out” and see that a tank is almost spent. If you notice that the tank feels really light, chances are that you’re dealing with a spent tank.
  • The tank is being tapped, but no smell is coming out. This is usually a sign that your tank has been totally used, which means that you’re out of fuel.
  • There’s no flame being produced when you hook the tank up to your grill. No flame means no juice, plain and simple.
  • The flame isn’t coming out the right color. Propane heat is high, which means that you should expect a blue flame. If you’re getting a red one, chances are that your tank is about to tap out.

If your propane tank is empty, you have two choices. You can either get it refilled at a local propane store near you, or you can choose to properly dispose of the tank.

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Our Final Take

At first glance, propane tanks can appear to have no way to tell how much gas is left inside. However, that’s not really true. There are several methods you can use to figure out how much gas you have left. The two less accurate methods include using a pressure gauge and using the hot water method.

If you need a more exact reading, you are going to need to take the tank and weigh it. Once you do the math, you’ll be able to tell if you need to go shopping for more propane soon.

Finding a propane tank that could potentially have a gas in it doesn’t automatically mean that you should use it. It’s possible to get a tank that’s unsafe to use. Before you use that tank, check to see if a tank is safe to use. After all, no amount of propane use is worth risking harm to yourself.

Ossiana Tepfenhart
Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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