Propane tanks serve a variety of purposes, from cooking to heating to generating electricity. A home propane tank can be very useful, but deciding what size or weight you need for a particular task can be a bit tricky.

Common Propane Tank Sizes
One of the most common propane tank sizes is the 20-pound tank. This tank, which is 1.5 feet tall and 1 foot in diameter, is mostly used for propane grills, but it can also be used for outdoor items such as patio heaters or generators.

Tanks labeled as 33 pounds are not nearly as common, but they can be found powering machinery such as forklifts or large tractors.
These tanks are 2 feet tall and 1 foot in diameter.
One hundred and 120-pound propane tanks are a good choice for medium-sized tanks. These tanks are most often used to power one or, at most, two household appliances, such as a gas fireplace or a gas stove.
These tanks can be quite heavy but they’re still considered to be portable. Occasionally, two 100 or 120-pound tanks are connected and used together to avoid running out of propane.
A 100-pound tank stands 4 feet tall and is 1.5 feet in diameter, while a 120-pound tank is 4.5 feet tall and 2.5 feet in diameter.

The next tank size up is the 420-pound or 100-gallon tank. These tanks are excellent for powering generators or offering supplemental heating. They are 4 feet tall and 3 feet in diameter.
For a slightly larger propane tank, a 250-gallon tank is a good option. These tanks are 7 feet 10 inches long and 2 feet 6 inches in diameter.
They work well for either running two appliances, such as generators, water heaters, or fireplaces, or for supplemental heating.

The most common size for a residential propane tank is a 500-gallon tank. These tanks can power multiple appliances, and they’re also commonly used for heating.
They work well for homes of 2,500 square feet or more. A 500-gallon tank is 9 feet 11 inches long and about 3 feet in diameter.
The largest common propane tank size is the 1,000-gallon tank. This tank is about 16 feet 2 inches long and about 3 feet 6 inches in diameter.
A 1,000-gallon tank can be used for heating or running all of the appliances in a home or business. These tanks are most commonly found powering homes or businesses that are 4,500 square feet or larger or require an equivalent amount of power.

How much does a propane tank hold?
Although propane tanks are labeled by either weight or gallon size, this doesn’t always give an accurate idea of how much they can hold.
Large tanks, for example, that are labeled in gallons can only be filled to 80%. This means that if you have a 1,000-gallon propane tank, it can only really be filled with 800 gallons.
The 500-gallon propane tank holds about 400 gallons.
You can figure out how much a propane tank labeled by weight holds if you know how much a gallon of propane weighs.
One gallon of propane is equal to about 4.24 pounds, so you only need to divide the weight of the full tank by 4.24.
Using this method, we can find that a 20-pound tank will hold just over 4.5 gallons of propane. A 33-pound tank holds just under 8 gallons of propane.
A gallon of propane weighs about 4.24 pounds.
What size propane tank do I need?
When choosing the size of the tank, it’s better to err on the side of a larger tank. If you purchase a tank that’s too small for your needs, you may find that you run out of propane unexpectedly.
You will also need to have propane delivered more frequently, which can cost more money in the long run. Larger tanks, however, are a more expensive initial purchase, and they can be more difficult and expensive to install.
To find out what size tank is best for you, add up what appliances will run off of it, decide if you’ll use it for main or supplemental heating, and factor in the size of your home.
If you need a small propane tank to run a grill, farm equipment, or a generator, it’s a good idea to purchase two or more tanks.
This way, you’ll always have a spare if you need one, and you can use that spare until you get the original tank refilled.

Above-Ground vs. Underground Tanks
Most medium or large propane tanks can be placed either above ground or underground. Installing a tank underground can be more time-consuming and expensive, but it hides the tank almost completely.
This is often a great choice for large tanks. Above-ground tanks can often be hidden with fencing or landscaping, although they are often more visible than underground tanks. They cost much less to install.
