Home-How » 20 lb vs 30 lb Propane Tank (Which Is Better?)

20 lb vs 30 lb Propane Tank (Which Is Better?)

Say goodbye to the hassle and uncertainty of choosing the right propane cylinders for your home or outdoor activities. The 20 and 30 lbs are both popular choices, but which is best for your needs? That’s what we’re here to explore!

You’ll learn the key differences between the two, including their size, capacity, duration, cost, and much more. By the end of this comparison between 20 lb vs. 30 lb propane tanks, you’ll know exactly which propane tank is right for you.

20 lbs Propane Tank

Starting with the 20 lbs propane tank, according to Upgraded Home, the weight of a propane tank in this size is typically smaller and lighter than its 30 pounds counterpart. It weighs approximately 17 pounds when empty and 37 pounds when full, with a capacity of 4.5 to number of gallons which can fuel a wall or hot water heater for 14 hours straight.

A 20 lbs propane tank is often called a grill cylinder in a cylindrical shape like other propane tanks with a carrying handle. It is preferred for outdoor cooking and grilling, camping, and a small space heater. Its portability and manageable size make it easy to transport, store and handle, making it ideal for those who want to take it with them on the go.

  • Pros: compact and easy to handle
  • Cons: has a lower capacity and may not last long for frequent usage
20 lbs Propane Tank
Image Credit: bargainmodder

30 lbs Propane Tank  

On the other hand, the 30 lbs propane tank weighs approximately 25 pounds when empty and 55 pounds when full, with a capacity of 7 gallons of propane. This tank is larger in size and propane weight, making it less portable than the 20 lbs tank. Like 20 lbs propane tank, 30 lbs also requires an Overfill Prevention Device or OPD valves to avoid overfilling.

The increased size of the 30 lbs tank allows it to store more propane, making it a good option for those who use propane for a stove, dryers, a fridge on camper trailers, or those who have larger home heating or outdoor cooking needs. The larger size of the tank also makes it more challenging to handle and transport, but it can be a good choice for those who do not need to move the tank around often.

  • Pros: offers a larger capacity and less frequent fills
  • Cons: heavier and may be difficult to find propane filling stations

To help you choose between the two, we cited this online forum from users who said that having a single 30 lbs tank requires filling it before it runs out, resulting in wasted gas and less value for money. This also means risking half-cooked meat since you have to run and fill the tank. And mind you, it’s harder to find refills for 30 lbs tanks than 20 lbs tanks.

That is why other users suggested just getting two 20 lbs tanks to swap when one runs out before filling up the empty one and storing again for the next use.

30 lbs Propane Tank  
Image Credit: 1bad_duc

20 lb vs. 30 lb Propane Tank (Size, Duration, Cost)

20 lbs vs. 30 lbs Propane Tank Size Comparison

The 20 lbs propane tank dimensions are approximately 18 inches in height and 12.5 inches in diameter, making it the smallest option. On the other hand, a 30 lbs propane tank measures around 24 inches, six inches taller than 20 lbs propane tank, but has the same diameter size.

1. Duration

The duration of a 20 or 30-pound propane tank largely depends on how much propane is being used and how often. A 20 lbs propane tanks usually have a BTU (British Thermal Unit) Capacity of 430,270, while a 30 lbs propane tank has a 649,980 BTU capacity.

On average, a 20-pound propane tank can last between 18 to 20 hours of continuous use on a medium-sized gas grill. The approximate burn time for a 30-pound tank is about 22 hours if connected to the tongue of the trailer or 1 to 2 weeks of everyday cooking. This can vary depending on factors such as the size of the appliance being powered and weather conditions. Keep in mind these are rough estimates, and actual usage may vary.

2. Cost  

Prices change over the years due to the surges in propane prices. Most propane refills are priced per gallon, which ranges from $2 and $6, and obviously, 20 lbs propane tanks will cost a little bit of money compared to 30 lbs tanks. Depending on the brand, retailer, and location, you’ll pay $20 or more for every refill of 20 lbs propane tanks. Take a look at the refill cost chart for 20 lbs propane tanks made by Learn Metrics.

How to Safely Fill The Propane Tank

Before filling your empty propane tanks, check for these three things: a triangular valve on the top, damages, and the printed date.

The valve is used to open the tank. If you see the triangular shape or the letters OPD valve print, it’s okay to fill the tank. If the valve is not triangular, do not fill the tank, as it is unsafe. It’s also dangerous to refill or use damaged propane tanks, and lastly, LP tanks with over 12 years of printed date need to be recertified every 5 years. Make sure you have recertified yours before refilling it.

If you’ve checked that everything is well, you can proceed to refill your propane tanks with these steps provided by the wikiHow website.

Step 1: Weigh your tank.

To get an accurate reading of your propane tank’s full weight, ensure that your scale is reset to zero before placing your empty tank on it. The weight of the tank should have the exact weight as your Tare Weight. If there’s a difference in number, it only means your tank still has propane left.

Step 2: Connect the tanks with a connector hose.

Ensure the hose has propane fittings on both ends and is long enough to reach both tanks. To connect the hose, screw it onto the port on your empty tank and tighten it with a wrench to prevent leaks. Then connect the other end to the port on the supply tank.

Step 3: Open two valves.

First, turn the valve on the empty tank to the left (counterclockwise), so propane can go inside. Then, do the same thing with the valve on the full tank. When you hear a hissing sound, it means both valves are open, and propane is moving through the hose.

Step 4: Fill the tank with cold water.

Do this using a garden hose. This ensures the propane can transfer between tanks and are at different temperatures. Start by turning on the hose to a weak stream and holding the nozzle on top of the tank. Let the water run down the sides, and cool the tank while filling it up.

Fill the tank with cold water
Image Credit: dobsongiftsandhardware

Step 5: Close the valve.

Remember to only fill the propane tank at a maximum of 80% capacity. Once the tank weighs the correct amount, turn both valves of the tanks to the right to close them.

Step 6: Turn the bleeder valve open.

To open the bleeder valve, use a screwdriver to rotate the screw counterclockwise. This is to ensure your tank isn’t full. Let the liquid flow out until only gas or vapor is released. Then, turn the screw clockwise to close the valve. Remember to wear safety gloves when you do this.

You should be safe when you follow these steps. However, bulk propane filling is no longer the way to fill propane tanks in the local gas station in Canada and the United States as safety organizations are working to ban such stations. Instead, people are using the exchange program where you can swap empty tanks at local grocery stores and Walmarts with a new full tank.

This means they bring their empty tank to a particular propane yard, where it gets checked, tested, and filled up again. This change is because of safety issues, like accidents at gas stations where people fill up their propane tanks. These accidents happened because of the loss of too much propane vapor, a lack of proper inspection of customers, faulty information, and a lack of user’s own discretion.


Q1: How do I know the weight of my tank when empty?

Look for the collar of the tank for the combination of numbers and letters for the weight of your propane tank. It usually looks like this: WC – xx LB TW – xx LB

WC – xx LB TW. The xx is the water capacity the tank can hold.

TW – xx LB. The xx is the number that tells the size of the propane tanks without the propane loads.

Note that the number indicated in TW (Tare Weight) is only 80% of the propane tank’s capacity to allow for expansion at high temperatures. Overfilling propane tanks may lead to leaks and explosions.

Q2: Can I use 20 lbs and 30 lbs propane tanks interchangeably?

Yes. Regardless of the tank size, the propane fuel in the tank has the same properties. They usually come with the same valve, and both can accept the connector on the hose connected to your grill.

Q3: How do I know how much propane is left in my tank without a gauge?

You can weigh the tank on a scale to estimate how much propane is left. Look for your tank’s Tare Weight (empty weight) and subtract it from your tank’s total weight. The answer is the remaining propane in your tank. But you can also use the hot water method.

When you pour hot water on the side of your propane tank and feel for a cool spot, the top of that spot shows how much propane is left. According to CNET, this happens because the liquid propane inside the tank takes in the heat from the hot water, which makes the metal wall feel cool where the propane is and warm where it’s not. Watch this Youtube video below for your guide.


To summarize, the 20 lb vs. 30 lb propane tank debate is personal; the right choice for you will depend on your individual needs and preferences. In addition to the factors we discussed, it’s also important to consider the frequency of your use and the availability of propane refills in your area. We hope this guide has provided you with the information you need to enjoy the benefits of a reliable propane fuel source for all your outdoor and indoor activities.

Leave a Comment