/ / How Long Does a 20lb Propane Tank Last: 3 Methods For Measurement

How Long Does a 20lb Propane Tank Last: 3 Methods For Measurement

If you don’t know how long does a 20lb propane tank last, then worry not. Today, we’ll explore its run time depending on the equipment’s power and three reliable methods to measure the lifespan of your propane tank. We will also discuss places where you can easily refill these tanks. Let’s dive into the details!

An Insight into Propane Tanks

A propane tank is a portable storage container specifically designed to hold the gas:

How Long does a 20lb Propane Tank last. An Insight into Propane Tanks
  • It is a versatile fuel commonly used for various applications like cooking etc.
  • It has a cylindrical or rectangular shape and is made of durable materials such as steel or aluminum.
  • A portable propane tank is capable of withstanding high pressures.
  • It can come in different sizes, with a 20lb tank being a popular choice for residential use.

These tanks serve as a convenient and reliable source for various purposes such as:

  • Heating
  • Grilling
  • Powering Various Appliances

Let’s check out the duration of various heater sizes on a 20lb propane tank:

Equipment Power in BTU

(British Thermal Unit)

Run time of a 20lb Propane Tank

7,500 BTU

57 hours

10,000 BTU

43 hours

15,000 BTU

29 hours

20,000 BTU

21 hours

30,000 BTU

14 hours

3,5000 BTU

12 hours

40,000 BTU

11 hours

50,000 BTU

8.5 hours

60,000 BTU

7 hours

80,000 BTU

5.5 hours

So, if you know how many BTUs are being used, you can easily figure out the run time of even a large propane tank.

Duration of 20lb Portable Propane Tanks

Here is the duration of 20lb propane tanks if you’re using a 9000 BTU portable heater:

Daily Heating Duration

Lasting Time

2 hours

19 days

4 hours

10 days

6 hours

6 days

8 hours

5 days

10 hours

4 days

12 hours

3 days

14 hours

3 days

A 20lb propane tank can last for approximately a week when used for heating purposes. It is when assuming a daily usage of 4-6 hours.

Duration of 20lb Portable Propane Tanks
Important! It’s essential to note that individual usage patterns and the efficiency of the heating equipment can affect the actual duration. Also, don’t forget how many BTUs consumed affect propane usage. More BTUs = More propane usage.

Understanding the Capacity of a 20lb Propane Tank

A 20lb propane tank typically holds 16lb of propane gas as it is filled up to 80% of its capacity. This filling level accounts for the temperature sensitivity of propane:

  • It expands 17 times more than air with each degree of temperature increase.
  • If these tanks were filled to 100% capacity, the internal pressure would fluctuate significantly with changes in outside temperature resulting in leaks or explosions.
  • By leaving 20% of the tank empty, there is sufficient space for the propane to contract and expand.
  • It ensures stable pressure levels and safe usage.
Understanding the Capacity of a 20lb Propane Tank

Exploring the Propane Tank Sizes Used in RVs

RVs can have varying types of propane tanks. Smaller and towable RVs typically have 1 or 2 cylinders.

  • Some have ASME tanks. Their capacity is about 33 pounds.
  • Some can use 20 lb propane tanks which are sufficient enough for most use cases.
  • Larger ones often feature bigger tanks with some holding up to 100 lbs.
Exploring the Propane Tank Sizes Used in RVs
Note: It’s worth noting that it’s possible to attach a grill with the ASME tank for added convenience.

Let’s discuss some of the appliances that are powered by propane:

Propane-Powered Appliances

The propane amount being used varies a lot when using different appliances. Here is how the following appliances use propane:

  • Furnace: The furnace is the most propane-intensive appliance in an RV. It provides high heat for the interior space. It uses 1/3 gallons of propane per hour so if you’re using a 20-pound tank, it will last you a week.
  • Portable Propane Heater: It offers efficient high heat and surpasses the built-in furnaces in terms of energy-saving capabilities. A propane heater uses about 0.25 to 0.35 pounds of propane per hour.
  • Stovetop and Oven: These generally require minimal propane usage. It also depends on the frequency and duration of cooking activities. In this case, you’re looking at a consumption of 0.4 to 0.6 gallons per hour.
  • Water Heater: Propane consumption in water heaters depends on factors like shower frequency, dishwashing habits, and the availability of shore power. It takes about 0.35 gallons/hour but it will vary with usage.
  • RV Fridge: RV fridges are highly efficient and consume minimal propane to maintain proper cooling. It makes them very fuel-efficient. It burns around 1.5 gallons of propane/day.
  • Generator: Some RVers go for propane-powered generators. But the consumption varies heavily with the duration and frequency of generator usage. If you’re using a 5000-watt generator, it will take about 1-1.5 gallons of propane per hour.
Propane-Powered Appliances

Estimating The Remaining Fuel in a 20 lb Propane Tank

Using these simple methods, you can easily determine how much quantity is left in the tank:

1. The Hot Water Method

It is one of the simplest methods that you can use. Just follow these steps:

  • Take water in a container and heat it up.
  • Tilt the tank slightly and start to pour the water over it.
  • Stand it upright and place your hand on the surface of the tank. You now have to feel the metal’s temperature.
  • Note the point where it transitions from warm to cold. This is your current level.
  • Based on it, you can estimate the approximate weight of propane remaining.

The tank will be roughly full if you notice the mark at the halfway point. This method allows you to make an estimation of how much propane is left in your tank.

The Hot Water Method

2. Using a Scale

The 2nd method is by using a scale through the following steps:

  • Locate the Tare Weight marking on the tank. This indicates the weight of the empty tank without any gas. It is typically around 17lb.
  • Use a scale to measure the weight.
  • Subtract the tare weight from the total weight to determine how much propane remains in the tank.
Using a Scale
Example: If the total weight of the tank is 27lb and the tare weight is 17lb, you can calculate the propane remaining by subtracting the tare weight from the total weight. It would be 27 – 17 = 10lb of propane left in the tank.

A digital scale like the Ozeri further simplifies the process:

  • It features a colored gauge and a digital display for instant weight readings.
  • It is compact and can easily fit in your accessories bag.
  • You can use it to measure large stationary propane tanks.

But if you prefer a more advanced option, you can try another one like the Flame King Smart Wireless Propane Tank Scale.

  • It is a smart scale that directly connects to your smartphone with Bluetooth.
  • It can be placed under your tank and provides real-time updates on your propane usage when using patio heaters or a medium-sized grill.
Flame King Smart Wireless Propane Tank Scale

3. Using a Pressure Gauge

The last method is by installing a pressure gauge. You can instantly monitor the different levels in the tank. In this way, you will know when it’s time for a refill.

Using a Pressure Gauge
Note: Keep an eye on the tank’s pressure as it will help in identifying potential overheating or over-pressurization issues. Thus, reducing the risk of explosions.

For further insights on the lasting of portable propane tanks, check out this helpful video.

Where to Refill 20lb Propane Tank?

A notable advantage of a 20lb large propane tank, as well as other large propane tanks, is their refillability. This eliminates the need to purchase a new cylinder every time the gas runs out. When your tank is running low or empty, you have two options:

  • Refilling it at a local station.
  • Exchanging it for a pre-filled tank.
Where to Refill 20lb Propane Tank?

The exchange option offers convenience as you can simply return your empty tank and receive a filled one on the spot, saving you time and effort.

Several retailers offer convenient exchange and refill points for propane tanks. Listed below are some of the best with good propane prices:

1. Walmart

These stores offer propane tank exchanges. It is really convenient to get your tank exchanged for a full one. You can visit this site for more information.

2. Home Depot

Similar to Walmart, they also take all types of empty propane tanks and replace them for you. Visit their website for more information.

3. Lakes Gas

It allows you to trade in your empty tank. You can find your nearest location through their website.

4. RapidXchange

These stations enable you to exchange cylinders for full ones. They have a wide presence across numerous states. Use their website for further support.

5. Blue Rhino

These stations also provide you with an exchange service. They accept tanks from other brands as well. To find the nearest Blue Rhino station:

  • You can text FIND to 75653.
  • Use their website’s locator tool.

6. AmeriGas

They offer propane tank replacement services. AmeriGa s also collaborates with third-party retailers to expand their reach. While not all stations provide tank exchanges, a lot of them do. To locate a nearby AmeriGas exchange location, follow these steps:

  • Visit their website.
  • Enter your zip code.
  • Apply the Propane Tank Exchange filter.

Tips for Maximizing the Lifespan of Your 20lb Propane Tank

If you are worried about how long will the propane tank last, then you should follow the handy tips listed below:

Tips for Maximizing the Lifespan of Your 20lb Propane Tank
  • Regular Inspection: Perform regular visual inspections of your 20 lb propane tank to check for any signs of damage, corrosion, or leaks. Addressing any issues promptly can prevent further damage and extend the lifespan of the tank.
  • Proper Storage: Store your propane tank in a well-ventilated and upright position. Keep it away from direct sunlight, heat sources, and flammable materials.
  • Regular Maintenance: Schedule regular maintenance checks with a certified propane professional to ensure your tank is functioning optimally. They can inspect the valves, fittings, and safety mechanisms to keep your tank in good working condition.
  • Efficient Appliances: Use an energy-efficient propane heater and other appliances that are designed to maximize fuel usage. Consider upgrading to newer models that have higher efficiency ratings.
  • Temperature Considerations: A Propane tank is affected by temperature fluctuations. Keep your tank in a moderate climate whenever possible.
  • Avoid Overfilling: Never overfill your 20lb propane tank. Leave room for expansion during temperature changes. Overfilling can lead to safety hazards and decrease the overall lifespan of the tank.


How long will a 20 lb propane tank last on a gas grill?

A 20 lb propane tank can last approximately 15-20 hours of grilling time. It depends on how many BTUs are being consumed.

How long will a 20 lb propane tank last at 50 000 BTU?

A 20 lb propane tank will last approximately 8.5 hours when used with a 50,000 BTU propane appliance.

How long will a 20 lb propane tank last on a Mr heater?

The duration a 20 lb propane tank lasts on a Mr. Heater will depend on the specific model and heat output settings. As a general estimate, a 20 lb propane tank lasts around 10-20 hours.

What is 20lb propane?

A 20 lb propane refers to a standard-size propane tank that holds approximately 20 pounds of propane gas. It is commonly used as a fuel source for various appliances, such as patio heaters, etc.

How big is a 20 lb propane tank?

A 20 lb propane tank stands about 18 inches tall and has a diameter of approximately 12 inches. Its capacity allows it to last for several hours.


Understanding how long a 20 lb propane tank last is essential for an average consumer. It will come in handy when planning an adventure or managing cooking at home. By using hot water, a scale, or a gauge, you can easily measure the current capacity. Also by considering factors like BTU ratings and appliance efficiency, you can estimate the tank’s lifespan accurately.

Remember to prioritize safety, regular maintenance, and proper storage to maximize the lifespan of your propane tank. Whether it’s grilling or camping, a well-managed propane tank ensures you have a continuous supply of fuel for your outdoor adventures.

How much does your tank last? Share your experience in the comments!

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