If you’re looking to power a generator with propane, you’ll need to choose the right size tank. A small generator may only require a 20-pound tank, while a larger one could need a 120-500-gallon tank. It’s important to select the correct size tank so that your generator will run smoothly and efficiently.
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Generator Propane Tank Sizes
There are a few factors to consider when sizing a propane tank for a generator. The first is the generator’s power output. The second is the runtime of the generator. And the third is the climate.
A generator’s power output is measured in watts. The higher the wattage, the more power the generator can output. The runtime of the generator is the amount of time it can run continuously before needing to be refueled. And the climate is the average temperature in the area where the generator will be used.
In general, a generator will need about 4 watts of power for every hour of runtime. So, a generator that can run for 8 hours will need 32 watts of power. And a generator that can run for 24 hours will need 96 watts of power.
If the climate is colder, the generator will need more power to keep the engine warm. In general, a generator will need about 8 watts of power for every degree below freezing. So, in a climate that is 20 degrees below freezing, the generator will need about 160 watts of power.
To size a propane tank for a generator, you will need to know the power output of the generator, the runtime of the generator, and the climate. With this information, you can determine the size of the propane tank that you need.
How Much Does It Cost to Run the Generator
We can’t exactly determine how much you’re going to spend to run the equipment. There are many other factors that come into play, and everything varies, that’s why it is difficult to give an exact amount to run the generator. The factors are the following:
- Propane consumption – that depends on the load, and the max-rated output of the equipment
- How long you intend to run the generator – the longer it runs, the more propane it consumes, and the more costly to put it in continuous operation.
- The number of appliances in the home that consume electricity.
- The max rated output of the generator – the most common is the 5kw-20kw which is ideal to power a residential house.
To give you an approximate computation of how much you need to spend, read below.
What Size Propane Tank Do You Need for 22kw Generator
The tank size you need for a 22kw generator will primarily depend on how long you intend to run the generator. Considerably, a 120-gallon propane tank is sufficient to run the equipment for about 36-48 hours on average. For larger tank, let’s say a 500-gallon tank, the generator can run for about 9 days without stopping.
To make a computation on how much propane it consumes, a 22kw generator consumes about 2.5-2.8 gallons per hour; If the propane is at $2.75 per gallon, that is approximately $165-$184 per day of operation. This is just a conservative computation, consumption will also depend on the load of the generator.
What Size Propane Tank Do You Need for a 20kw Generator?
Again, a 20kw generator there isn’t much difference from a 22kw. The most common tank size for a 20kw generator is the 120-gallon, this is enough to power the generator for approximately 52 hours on average. While the 500-gallon tank will run the generator for about 220 hours.
But just being 20kw, it consumes a little less fuel. You can expect to spend about $150-$160 per day to run the generator. Then again, a full-load generator in continuous operation will consume a lot of fuel. Everything will depend on the load the generator handles at a given time.
Those figures mentioned above are just a rough estimate. Propane prices vary from state to state so it is not possible to determine an exact amount. The aspect is the appliances that consume electricity, the more appliances that are turned on at a given time, the more fuel the generator consumes.
A 20lb Propane Tank Can Give a Short Run
A 20-pound tank you might have stored in your home will run the equipment for about six hours. A 20-lb propane tank can hold 4.6 gallons of propane, which is not enough to run the generator for a long period obviously. So, depending on the propane load in the tank, the operating period may vary.
The other factors are the wattage of the equipment. Nowadays, there are 4000-watt, 5000-watt, 7500-watt, and 10000-watt available in the market that run on propane and model and brand of the equipment.
Small Vs. Large Tanks
A propane tank is an essential piece of equipment for running a generator, and it is important to choose the right size tank for your needs. Propane tanks come in a variety of sizes, from small portable tanks to large stationary tanks. The size of the tank you need will depend on the size of your generator and the amount of propane you will need to store.
Small portable propane tanks are typically used for generators that are 5,000 watts. These tanks hold between 20 and 40 gallons of propane and can be refilled at most gas stations. Larger portable propane tanks are used for generators that are 10,000 watts or more. These tanks hold between 100 and 200 gallons of propane and can be refilled by a propane company.
Stationary propane tanks are typically used for generators that are 25,000 watts or more. These tanks can hold up to 1,000 gallons of propane and must be installed by a professional.
To Make a Finalization
If you have a generator that uses propane, you need to have a propane tank that is large enough to hold enough propane to run the generator for the amount of time that you need it. There are several sizes of propane tanks, so you need to determine the size that you need based on the size of your generator and the amount of time that you need to use the generator. The larger the tank, the more propane it will hold and the longer the generator will run.


Mike is an experienced propane technician with over 15 years of professional experience in the field. He has dedicated his career to helping customers with their propane needs, from installation to maintenance and repair. Together with Jeremy, he co-founded this website to provide useful information and guidance to customers seeking reliable propane services.