How Many Gallons in a 100-lb. Tank? The Detailed Answer

Rodney Nestor
Rodney Nestor
Research Writer
Rodney holds a Master’s degree in Arts and apart from working as a freelance writer, is a rather successful author of science fiction stories published in several literary read more
Last updated: September 03, 2023
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As homeowners and propane gas consumers, it’s important to know how much your propane tank weighs and how much it can store. One of these is to know how much propane is in a 100lb tank upon purchase or installation to serve as information for subsequent usage. This has an extremely simple answer to it but we need to do a few breakdowns for a better understanding. Now, propane tanks are designed to hold a specific quantity of propane (20lb, 30lb, 33lb, 40lb, 100lb, 500lb, and more), and a 100lb propane tank holds 100 pounds of propane. Liquids are measured in gallons and not weight. So, how many gallons does a 100lb propane tank hold? Propane is stored and distributed as a liquid for usage so, you need to know how many gallons of propane each tank size can hold and how many are in a 100lb tank.

Dimensions of a 100lb Propane Tank

A 100lb tank is approximately 48 inches tall by 14.5” in diameter, and has a capacity of 2,160,509 BTU (British Thermal Units). Now, let’s break it down for better understanding, and convert pounds to gallons because propane weighs in pounds per gallon.

1 pound of Propane = 0.236 gallons. This is the case when the propane tank temperature is 60 degrees Fahrenheit.

1 gallon of Propane = 4.24lbs (by weight)


100 pounds of propane = (100 x 0.236) 23.6 gallons

So, a 100lb tank holds 23.6 gallons of propane and weighs about 170 pounds when full.

It is quite important to note that other factors can affect the overall usage in your propane tank, and this mainly sits with your propane tank supply. These main factors include temperature and water capacity. Both can affect your propane tank and its supply so, it is safe to keep an eye on them. Lower temperature can cause your tank not to work properly so, you must refill frequently as soon as your propane level is down to ensure a balanced pressure.

FAQs on 100lb and Other Propane Tank

Why aren’t propane tanks 100 percent full?

It is true propane tanks aren’t always 100 percent full and this is not to rip off customers. The main reason for this is because propane expands when heated and the space left will fill in for this. This is where the 80 percent rule applies, most tanks will be filled up to 80 percent.

How long does a 100lb tank last?

This is largely dependent on the level of usage. The more you make use of propane, the more it burns out. By calculation, the burn rate of one gallon of propane equals about 92,000 BTUs per hour. If an 80,000 BTU machine is running for 24 hours, 7 days, then propane will last for 1.125 days. If such a machine runs for 12 hours, then it can last up to 2.25 days. It is very important you know the burn rate of your appliance to be able to find out the number of days it can last for.

Can I use a small propane tank for a grill?

How Many Gallons in a 100-lb. Tank? The Detailed Answer

Making use of a small propane tank is generally suitable for a small space and little usage. Most businesses and large homeowners find this impartial. But to be cost and energy effective, you should go with a propane tank that fits your usage style and time to avoid hassles. Although the most popular tank size is 20 pounds.

What is the average price of propane?

Starting from $5, propane peaks at $3500 and an average of $800- $1000. Due to its versatility and usage level, hiring a professional or a company’s expertise to help with sizing, designing, and determining cost will help the most.

How many BTU is in a pound of propane?

1 pound of propane = 21,548 BTU (British Thermal Units) of energy

How much does an empty 100lb propane tank weigh?

Many 100ln propane tanks weigh approximately 67 pounds when empty before filling.

Does propane gas have an expiration date?

Propane doesn’t expire. Propane itself will not break down when properly stored as there will be nothing to react to right from the tank. The only factor that could be a problem here is the tank used for storage. If the storage tank gets rusts, it can leak or cause a hole and this will be very dangerous.

What home size do I need for a propane tank?

A home should be at least 2,500 square feet. That’s the ideal home size. And if you have a small space, it’s all well and good, and the number of appliances will vary in this case as propane will be used for different purposes and different devices.

 Are Propane tanks safe to use?

How Many Gallons in a 100-lb. Tank? The Detailed Answer

The simple and straight answer is yes! Propane tanks are the safest and they require proper handling to ensure your safety. By exercising caution, propane is one of the safest sources of energy to use. Make sure you understand the nature and basic safety precautions, and this will make you feel comfortable and rest assured when using it. Always wear protective clothing, and gloves before coming in contact with your propane cylinder and the release valve.

When should I worry about my propane tank?

If after searching around the house and you can’t find anything that could properly be the cause, you may have a tank leak. This may be a skunk smell or rotten egg smell. Although propane is naturally odorless, users are protected by odor added by manufacturers to alert them of danger. So, the wisest thing to do in this situation is to first, turn off the supply verve on your tank and ensure nothing flammable is anywhere close to the tank, and get help from professionals as soon as possible.

How do I maintain my propane tank?

As a first-time propane user, this may be intimidating but no worries, we’ve got the right answers.

  • Schedule regular maintenance that is servicing both propane appliances and the propane tank by qualified professionals.
  • Understand the impact of temperature on your propane tank
  • Check for leaks from time to time
  • Make sure your tank sits on a leveled ground

Final Thoughts

It is one of the important things to know how much propane your tank or cylinder can store. Your 100lb propane tank has quite enough capacity and how much you use and manage it matters. Now that you know how many gallons your 100lb propane tank contains, ensure that you do a quality check for each appliance from time to time to avoid running out of gas. Stay in the know, always!

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