How Long Does A 500-Gallon Propane Tank Last?

Of all the residential propane tank sizes, the 500-gallon propane tank is by far the most commonly used in homes. When the cold winter hits, you need to be ready to heat up your home. The most important thing is to NOT run out of propane. How many times will you need to refill per winter? And what's the 80% max propane tank rule? Let's find out!

How Long Does A 500-Gallon Propane Tank Last

Propane is used in a variety of ways inside many households. It helps with everything from cooking to heating and even drying clothes. Having a steady supply of propane is important for many homes to operate properly.

Many homeowners rely on 500-gallon propane tanks to meet their household’s fuel needs. How long can you expect that 500-gallon propane tank to last?

With the average US household consuming around 750 gallons of propane per winter, a 500-gallon propane tank will last between 2 to 14 months. The exact time will depend on the size of your home. For example, a 2,300 sq ft home (median size of a US single-family home) will consume between 700 gallons and 1,014 gallons. Most homeowners consume around 2 full 500-gallon propane tank fills every winter.

Knowing how long your 500-gallon tank of propane will last is important. Find out more about how to keep tabs on your propane supply and other relevant topics by reading on.

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Related Content: Can You Store Propane Tank In The Garage? | Can You Overfill A Propane Tank? | Can Propane Tanks Explode? | How To Check Propane Tank Levels

Average US Household Winter Propane Consumption

On average, a US household will consume at least 700 gallons of propane every winter. Source: US Energy Information Administration

Which Factors Affect Your Home’s Propane Consumption?

  • Your home’s size. Larger homes need more heat and therefore will consume more. A 500-gallon propane tank will run out much faster for 4,000 square foot homes versus the average 2,000 square foot home.
  • Winter conditions. In severe winters with harsh weather, the consumption is increased in comparison to the average winter. In 2013-2014 we had the harshest winter to date, with the average US home going through about 830 gallons of propane. In comparison, in most winters we consume just 750 gallons of propane.
  • Heating needs by location. Homes in the Northeastern part of the US require a much higher BTU heating output. This is a comparison to homes in the Southern part of the United States. For example, a 500-gallon propane tank will last longer in Oklahoma than in New Jersey.
  • Device’s energy efficiency. High energy and efficiency propane furnaces with a rating of more than 90 AFUE will consume way less propane for the same heating output. This is in comparison to, for example, a furnace that’s rated at 70 AFUE. With the 90 AFUE furnaces, a propane tank will last longer.
  • The 80% safety rule. Your 500-gallon propane tank can hold exactly 400 gallons of propane, despite what the name suggests. Space must be left in the tank to account for the expanding properties of propane and filling it to the brim could be dangerous. Your 500-gallon propane tank should never be filled to more than 80% capacity for safety reasons.

How Much Propane Do We Consume Per Winter?

The average US single-family home, which is around 2,300 sq ft, consumes an average of  700 gallons of propane every single winter.

And, if we want to calculate just how much propane we consume per square foot, here’s a neat formula:

1,014 Gallons Of Propane ÷ 2,300 Sq Ft House = 0.441 Gallon Of Propane Per Sq Ft

By using this formula, we can then figure out propane consumption (in gallons) for various home sizes:

Home Size by Square Footage Propane Consumption (In Gallons)
500 sq ft 220 Gallons
1,000 sq ft 441 Gallons
1,500 sq ft 666 Gallons
2,000 sq ft 888 Gallons
2,500 sq ft 1,110 Gallons
3,000+ sq ft  1,300+ Gallons

Propane Consumption by Appliance

Appliance Average Monthly Usage
(in gallons)
Average Monthly Cost
(based on 2015 average price of $2.60)
Propane Furnace 80 $208
Hot Water Heater 20 $52
Propane Fireplace 16 $42
Propane Stove Ranges 3 $8
Propane Clothes Dryers 1.5 $4
Total Estimated Monthly Cost $314

How Long the 500-Gallon Tank Will Last

As we know, due to safety, a 500-gallon propane tank is only filled up to 400 gallons. While we fill propane tanks up to 80% of their full capacity, we still achieve an energy content of 36,600,000 BTUs at 100% efficiency.

But before we dive into the chart, let’s figure out a way to calculate propane consumption based on your home’s size.

Based on average calculations, it’s safe to say that a 1,500 sq ft will consume at least 666 gallons of propane in 6 months’ time. But since we don’t really have 500 gallons in the tank, we have to calculate based on 400 gallons.

400 Gallons × 6 Months ÷ 666 Gallons = 3.603 Months

What it means is that a full 500-gallon propane tank will last about 3 and a half months and for a 1,500 sq ft home.

Now that we looked at an example, let’s see how long it’ll last for your home.

500-Gallon Tank Longevity

Home  Size by Square Footage 500-Gallon Tank Longevity
500 sq ft 14 Months and 4 Days
1,000 sq ft 7 Months and 2 Days
1,500 sq ft 4 Months and 6 Days
2,000 sq ft 3 Months and 25 Days
2,500 sq ft 2 Months and 25 Days
3,000 sq ft 2 Months and 11 Days
3,500 sq ft 2 Months and 1 Day
4,000 sq ft 1 Month and 23 Days

Please keep in mind that these numbers are based on statistical averages and are simply estimates. Consumption will vary per home, but it should be pretty close to these numbers.

Cost To Fill a Propane Tank

It can be expensive to fill a propane tank, especially if the tank holds 500 gallons. You can expect to pay an average of $600, or even more, to fill your 500 gallon propane tank. The total cost can vary based on the market price of propane at any given time.

If the market price of propane is $1.50-$2.00 per gallon, 400 gallons comes out to between $600 and $800.

How often you refill your tank depends on how much propane you go through as a homeowner. Generally, a household that’s over 2,500 square feet can consume 100 gallons in 30-45 days. At that rate, you could refill your tank as much as 3-5 times per year, costing you $1,800-$3,000.

Average Cost of Propane Per Year

The average cost for propane per year is between $2,000 to $3,000. While this cost is definitely more expensive than the consumption of electric appliances, it is still less expensive than oil and more efficient than both of them.

Cost To Install a Propane Tank Unit

The tank and propane itself are not the only costs of a 500 gallon tank, and installation is a big one. Underground propane tanks are expensive to install, especially for 500 gallons, and can cost up to $2,000. Above-ground propane tanks typically come out $1,500 after you have it professionally installed as it is labor-intensive.

Professionals have to haul the tank to your home and install it making for many hours of labor. You can technically install a 500 gallon propane tank on your own, but it is quite difficult and potentially dangerous. Call around and get installation quotes to get a feel for the difference in labor and installation costs from professionals.

How to Make It Last Longer

You can extend the life of your 500-gallon propane tank if you use it wisely and take precautions. The easiest way to make it last longer is to simply turn your thermostat down by up to 15%. You don’t necessarily need to make the house cold, but you can make a huge difference in longevity with a 10%-15% decrease.

Up to 300 or more gallons of propane will be dedicated to hot water usage per year in most households. Limiting your hot water usage can not only make your propane tank last longer, but it can save money. Taking shorter showers and limiting how long your sink runs is the best way to liberally use hot water.

Your furnace could consume as much as 1,000 or more gallons of propane each year alone. This puts stress on the propane tank and it increases your bills each month. If you shut your furnace off when you leave the house or go on vacation, you can extend the life of your 500 gallon propane tank.

When Should You Get Your 500-Gallon Propane Tank Refilled?

We’ve already established that 500-gallon propane tanks can supply enough fuel to last for at least two months. Keep that tidbit in mind and use it as a reminder to check up on your propane tank.

What you don’t want to do though is to wait until the five-month mark to check on the tank’s propane levels. Instead, make use of a gauge to determine how much propane is left in the tank.

You can attach a gauge to your propane tank and refer to it when determining how much fuel is left. Propane tank gauges are percentage-based. If their marker is pointing to 50 that means there are 250 gallons of propane left inside.

As a general rule, homeowners are advised to get their tank refilled once the gauge hits 20 percent. You shouldn’t let it fall below that mark.

Why the Propane Level in the Tank Should Never Fall below 20 Percent

There are important reasons why you should avoid allowing the fuel level to drop below 20 percent. Safety is foremost among them.

Draining the propane tank completely means that only air is left inside. Allowing potentially moist air to linger inside the air can lead to the formation of rust. If you consistently drain the tank before refilling, its inner walls may start to rust over and weaken.

Another concern here is leaking. You may have left the gas lines open because you forgot to shut them off with the tank drained. Now that a newly refilled tank is back in place, some of the propane may leak via those gas lines.

You also don’t want to find yourself in a position where the propane is running out a bad time. Enduring a cold night with no heat is unpleasant and bad for your health. Avoid that dire situation by refilling the tank ahead of time.

Why Is the Propane Tank Never Completely Full?

After you’ve refilled your 500-gallon propane tank a few times, you’ve probably noticed something that seems odd. To be more specific, you may have noticed that the tank is never completely full according to the gauge.

That’s not an accident. Propane dealers intentionally fill a tank only up to 80 percent capacity on purpose. The reason why they refrain from filling it up completely is again due to safety. This is known as the 80% safety rule.

The propane inside the tank expands when exposed to warmth. Leaving some part of the tank empty allows the fuel to expand safely. If the tank is full, it could end up bursting after the fuel expands.

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Gary Evans

Gary Evans is passionate about home improvement. He loves finding out how to make improvements in the easiest, most practical, and most affordable ways. Upgrading his home kitchen is one of his ongoing hobbies. Gary is also a long-time content creator and enjoys spending his free time tending to his hydroponic vegetable garden.

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