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How Much Does It Cost to Fill a 20 LB Propane Tank?

I recently invested in a propane grill for our rental property. As you can imagine, the tank runs out fairly often with heavy use. Since propane costs are something I deal with regularly, I can give you all the details you need.

A 20 lb propane tank will cost approximately $14-$20 to fill. The rate you pay depends on the refill cost, usually $3- $4 per gallon. Since a 20 lb tank holds about 4.7 gallons of propane, multiply the cost of propane per gallon by 4.7. For example, $3 X 4.7 = $14.10.

Some people take advantage of a propane tank exchange, a service offered by many big box stores like Walmart, Lowes, or Home Depot. The exchange usually costs about $20 plus tax, but there are deals occasionally. Filling will typically save about $8.

A tank that has a built-in gauge like this one is recommended if you are considering purchasing a new tank. You can even pick one up on Amazon.

Price Factors of Filling a 20lb Tanks

Blue Rhino Tank Exchange
Exchanging is a convenient option

Besides the per-gallon price, the cost of filling a 20 lb propane tank can fluctuate based on four factors:

  1. The propane suppliers’ understanding of the term “full”- Some suppliers may only fill their tanks to around 15 pounds but charge for the fill 20.
  2. If you decide to participate in an exchange program- As previously stated, costs will usually be a bit higher to exchange vs. filling yourself.
  3. Whether or not the tank is empty when you go to refill it- Most folks will fill their tanks long before it is actually empty, thus reducing the overall cost.
  4. The air temperature outside during a tank fill- As the temperature rises, propane gas expands, resulting in less room in the tank.

Related How Many Gallons of Propane Are in a Tank (With Size Chart).

The Effect of Temperature

Depending on the tank’s temperature and the air outside when the tank is being filled, you could lose 1-2 pounds of propane. If the air surrounding the tank is cooler, more propane will be placed inside the tank. If the temperature outside is warmer, less propane will make it into the tank.

In colder climates, suppliers may be reluctant to fill the tank up to capacity. If this is the case, you can expect to pay less money for what people may advertise as a full tank. Hence, this location may record a full tank as less than the standard full designation (4.7 gallons). This will result in a lower price for a “full” 20 lb refill if you have your tank.

Don’t Overfill

20 lb tanks can hold about 20% more than 20 lbs but should not be filled beyond 20 lbs of propane. A propane tank needs this extra room to accommodate temperature changes. If a full propane tank filled in winter is brought into a warmer environment, the propane gas will expand. If the tank is too full, the temperature change could cause the tank’s pressure relief valve to release some propane into the air.

Be Skeptical of Sales

Propane suppliers may advertise sales. They could offer a full tank for a specific price. It is important to understand what they think full means. It may appear cheaper, but you may just be paying for fewer gallons than your unit is capable of holding.

Best Places to Get a Propane Tank Filled

There are a few national chains that provide propane refills. For your convenience, I provided the store locator links where possible.

To see the best gear for grilling just click here.

Tank Purchase Cost Versus Refill Cost

Cartoon Propane Tank Running

The cost of buying your own propane tank and the amount of propane used throughout the year should factor into your decision of whether you choose the exchange or refill route.

Is It Cheaper to Refill Propane or Exchange?

On average, it is about $1.76 per gallon cheaper to refill a propane tank versus exchanging. Refilling your own propane tank costs about $3-$4 per gallon while exchanging is usually around $5-6 per gallon. However, many exchange programs only fill their 20 lb tanks with 15 lbs of propane.

This means you are being charged for a full tank while not getting a full 20 lbs of propane. This also means you will have to return to exchange your tanks more often. Ultimately, this means that the cost may very well be a wash. It’s up to you whether you prefer convenience or being more in control of filling your tank.

Exchanging Too Soon Can Be Costly

Most people exchange their tank before it is completely empty. If you exchange your tank before it is fully drained, you are basically lighting money on fire. So, if you frequently use the exchange program, you could be wasting a nice chunk of change.

Is Propane Cheaper if You Own Your Own Tank?

If you are frequently purchasing propane, then buying your own tank makes a lot of financial sense. You will pay less per gallon for propane, and you will pay less to refill your tank if you have propane left in the tank when you go to refill it.

If you seldom have a need for propane, it might not be worth purchasing your own tank. You will pay a little more using the exchange program, but you will not have the upfront cost of buying your own tank.

How Much Does a 20 LB Propane Tank Cost?

An empty propane tank can be purchased for about $35 – $60, depending on the brand, features, and quality. Having a built-in gas meter gauge usually increases the price by about $20 but may save you a lot of hassle in the long run since refilling too soon is a common issue.

You can either pick one up at a big box store like Lowes, Home Depot, or Walmart. Or, have it delivered to you from Amazon. If you are going to buy instead of exchanging, I highly recommend investing in one that has the built-in gauge, as pictured below.

How Many Hours Does a 20-Pound Propane Tank Last?

If you are using a medium-sized barbecue or grill, a 20 lb propane tank will last your about 18-20 hours. If you are operating a large grill, then you can expect your 20 lb propane cylinder to last about 10 hours.

How Many Gallons of Propane in a 20 LB Tank?

A 20 lb propane tank holds 4.7 gallons of propane. Propane weighs 4.24 pounds per gallon. To get the weight of a propane tank, you multiply the number of gallons by the weight of the propane. So, 4.24 x 4.7 = 20 lbs (19.928, to be exact).

Bottom Line

If you don’t mind spending a few minutes of extra time, refilling is a much better option, in my opinion. I would much rather be in control of how much propane goes in rather than being at the mercy of an exchange program. My advice is to get a quality tank with a meter gauge and refill yourself as needed.

I hope this article has been helpful. Thanks for reading!

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