How Long Does Propane Tank Last? (Find Out Now!)

Jessica Stone
by Jessica Stone

Not having enough propane is not only a major hassle, it can also be a danger. Whether you run out of fuel in the middle of a summer cookout or you don’t have enough propane to heat your home on a frigid winter’s night, it’s important to know the details surrounding propane tanks. More specifically, how long do propane tanks last?

The short answer is that it depends. How and the frequency at which you use your propane tank will play a major role in how long the fuel lasts. For example, with small, portable propane tanks (DOT), like those used for grills, their lifespan depends on the size of your grill and how often you use it.

With this in mind, let’s take a deeper look at how long propane tanks last, including the lifespan of some of the most common sizes, how to calculate burn rate, and the expiration date of propane tanks themselves.

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Common Sizes of Propane Tanks

The following are the most common sizes of propane tank cylinders and their associated specs:

  • 20 lb. tank: 18″ tall and 12″ in diameter; holds five gallons of propane.
  • 33 lb. tank: 2 feet tall and 1 foot in diameter; holds eight gallons of propane.
  • 100 lb. tank: 4 feet tall and 18” in diameter; holds close to 25 gallons of propane when full.
  • 420 lb. tank: 4 feet tall and 3 feet in diameter; holds 100 gallons of propane.
  • 500-gallon tank: 5 feet tall by 10 feet long; holds 400 gallons at 80% capacity (standard fill)
  • 1,000-gallon tank: 5 feet tall by 16 feet long; holds 800 gallons at 80% capacity (standard fill)

Propane tanks used for residential purposes usually range in size from 100 to 1,000 gallons. The smaller tanks, like the most common 20 lb. tank, is typically reserved for operating small appliances and outdoor barbecuing.

Homes that are 2,500 square feet or bigger, that have several appliances relying on propane, will likely have a 500-gallon tank. Whereas, tanks any bigger than 500-gallons are usually only found in commercial settings.

How Long Does a Propane Tank Last?

There is no one-size-fits-all answer to this question, as it depends the size of the propane tank, how you are using it, and how often. Let’s break this question down based on whether the tank is portable or non-portable.

Portable Propane Tanks

Portable propane tanks, also known as DOT tanks, are commonly used for water heaters, barbecue grills, and fireplaces. They may be anywhere from 20 lbs. to 100 lbs. Though, there are also the small 16 oz. tanks used for camping or powering motor homes. The amount of life that you get out of your portable propane tank, regardless of the size, depends on the size of the appliance it is fueling and how often you use said appliance.

As a general rule of thumb, a medium-sized grill on high heat will use roughly two pounds of fuel per meal. With this in mind, a 20 lb. propane tank will give you between 18 and 20 hours of cooking time when used with a medium grill. Whereas, a larger grill may be able to burn through the entire tank is just 10 hours.

Non-Portable Propane Tanks

While it may be a hassle to run out of propane when you’re in the middle of grilling, running out of the propane that heats your home or water can be hazardous in the middle of winter. For this reason, it is crucial to know how much fuel you use and how to know when you are running low.

Large propane tanks, also known as ASME tanks, are not portable. They are commonly used for heating homes and other residential applications, like water heaters and stoves. British Thermal Unit, or BTUs, is considered the industry standard for measuring the heating efficiency of household appliances. When calculating how long larger, non-portable tanks last, consider the following hypothetical usage statistics:

  • Cook stove: 63,000 BTUs
  • Furnace: 85,000 BTUs
  • Water heater: 199,000 BTUs

This brings the total BTU usage for this hypothetical home to 347,000. Divide this number by the number of BTUs in a gallon of propane (91,502) and you’ll will yield roughly 3.79 gallons of propane per hour.

However, this only applies if all of the propane-burning appliances are operating on high for the duration of the hours. Of course, this is not how we run out water heaters, furnaces, and stoves. They may kick on for 15 to 20 minutes out of the hour, or not at all. With normal usage, your burn rate is actually a lot less than 3.79 gallons per hour.

Propane Usage Statistics

How much propane you burn per hour also comes down to the size of your home and how hard your furnace needs to work to warm it. As you might expect, a smaller home will require less propane than a large home.

  • Depending on how often you turn it on, your home’s furnace will burn anywhere from 500 to 1,200 gallons of propane per year.
  • The average homeowner uses roughly 200 to 300 gallons of propane a year just for hot water.
  • The average homeowner can expect to use about 2.5, 500-gallon tanks (roughly 1,250 gallons total) of propane each year for heating and cooking.

Calculating Burn Rate

For the most customized way to find out how many hours of fuel your propane tank will give you or how much you have left, follow the steps outlined below:

  • The first thing you want to do is find out how much your propane tank weighs. This measurement is known as the tare weight, and is usually denoted on the tank itself.
  • Then, subtract this tare weight from the total weight of your tank with fuel inside.
  • Divide the total weight of your propane tank by 4.24 (4.24 pounds propane is equal to one gallon). This will make conversion easier going forward.
  • Next, you need to find out the BTU rating for the appliance you are fueling. For the sake of examples, let’s assume you have a propane grill that burns at a rate of 60,000 BTU per hour. This simply means that it will take 1.53 hours to burn 1 gallon of propane (92,000 BTUs in a gallon divided by the 60,000 rate of the grill equals 1.53 hours).
  • Divide the total number of gallons in your tank by the hourly burn rate of your appliance to find out how many hours of propane fuel the tank will give you.

Considering how complex these calculations can get, in some situations, it may be best to contact a professional.

How Long Does a 20 lb. Propane Tank Last?

The 20-pound propane tanks are the most common type of propane tank used for gas grills. When paired with an average-sized grill, a 20-pound propane tank will last approximately 18 to 20 hours on continuous use. So, if you’re grilling every day during the summer on an average-sized gas grill, the propane tank will last you between eight to 10 days if each grilling session lasts approximately two hours.

On larger gas grills, however, a 20-pound propane tank may only last you around 10 hours. The larger the grill, the more energy it consumes and the more fuel they require. How long your propane tank lasts can also depend on your cooking style. For instance, smoking requires less energy since only one or two burners are needed to provide indirect heat.

How Long Does a 16 oz. Propane Tank Last?

The 16 oz, or technically 16.4 oz, propane tanks are the most common energy source used for camping stoves and small portable heaters. They are also often referred to as a one-pound propane tank. While they are convenient, lightweight, and easy to use, many wonder how long these small propane canisters last.

Although there isn’t really a one-size-fits-all answer to this question, the general consensus is that a 16-ounce propane tank will last about 1.5 to 2 hours when cooking on high.

How Long Does a 100 lb. Propane Tank Last?

When completely full, a 100-pound propane tank holds nearly 25 pounds. If you want a distinct fuel source for your gas fireplace but don’t have the space to install a large propane tank, a 100-pound propane canister can provide many hours of fuel. How long a 100-pound propane tank lasts will depend on your fireplace’s consumption rate and how often you use it.

For example, if your fireplace has a consumption rate of 26,000 BTU per hour, a 100-pound propane tank will be able to service your fireplace for about 84 hours. This is equivalent to roughly 3.5 days of continuous operation. Whereas, if you only use your propane fireplace for two hours each day, seven days a week, a 100-pound tank will last you about six weeks.

How Long Does a 500 Gallon Propane Tank Last?

Many homeowners rely on 500-gallon propane tanks to meet the needs of their household, including everything from cooking and heating to drying your clothing. Having a consistent supply of propane is critical for many homes to operate properly.

The average homeowner typically refills their 500-gallon tank at least twice a year, as these tanks can meet household needs for roughly five months. Though, how long the tank lasts you will depend on the size of your home, the number of occupants, the number of appliances that rely on the propane, and the time of year.

How Long Does a 1,000 Gallon Propane Tank Last?

A standard 1,000-gallon propane tank is most suited for homes that are more than 4,500 square feet, but you must have a place outdoors to store it appropriately. For this reason, these tanks are most commonly installed for commercial and industrial purposes. They hold around 800 gallons of propane.

To estimate how long your 1,000-gallon propane tank will last, you need to how many propane appliances you have, as well as the size and efficiency of each. The average homeowner uses about 1,250 gallons of propane a year for heating and cooking. So, unless you have additional propane appliances, your 1,000-gallon propane tank will last you about a year.

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Do Propane Tanks Expire?

In addition to understanding how long the fuel in your propane tanks lasts, it’s also important to know how long the tank itself lasts. Propane tanks that have a capacity of 100 pounds or less (DOT) expire after 12 years from the manufacture date. Once the 12 years are up, you can exchange it for a replacement or have your tank requalified for five more years.

Note: You can find a tank’s date of manufacture or requalification stamped onto the collar. It’ll be present in a month-year format – for example, 11-21 for November 2021. If the tank has been requalified, it will have a ‘E’ or ‘H’ following the date.

Large propane tanks (ASME), like those used for hot water and heating homes, are governed by federal container laws. The laws state that such propane tanks can only be filled by the owner or an authorized individual. Since most home propane users lease their tanks from a supplier, they assume responsibility for keeping track of its expiration date.

These tanks are heavier, usually permanently mounted, and do not require the same recertification as DOT tanks. However, they should be visually inspected regularly.

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Jessica Stone
Jessica Stone

Jessica considers herself a home improvement and design enthusiast. She grew up surrounded by constant home improvement projects and owes most of what she knows to helping her dad renovate her childhood home. Being a Los Angeles resident, Jessica spends a lot of her time looking for her next DIY project and sharing her love for home design.

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