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How Long Does Heating Oil Last? (And How To Calculate Your Usage)

A lot of homeowners use heating oil to warm their home because it is one of the most comfortable and warmest heating methods available. This means oil tanks are a common component of houses in Pennsylvania and across the USA. If using an oil furnace is new to you, you may be wondering, “How long does heating oil last?” Based on our experience serving thousands of customers over the past 130 years, the short answer is:

On average, heating oil will last 18-24 months before it may become unstable. If too much moisture gets into your tank, however, the fuel can start to break down. This also will impede combustibility.

We only and always carry the highest-grade fuel oil and test it regularly. We also provide a special additive to optimize the efficiency and cleanliness of the burners as part of our oil delivery service.

Regular maintenance and quality fuel service will ensure that your furnace runs efficiently and you’ll get the most out of your home heating system. Let’s take a look at how long you can expect your fuel delivery supply to last throughout the year.

How To Calculate How Long Your Heating Oil Will Last

Let’s assume the nozzle in your oil burner sprays oil at an average flow rate of  1.7 gallons per hour. In 10 hours (the typical amount of time spent at home), you will have used about 17 gallons of heating oil.

Keep in mind, though, that it isn’t likely your oil furnace is going to run for that entire 10 hours.  Temperature range will impact the duty cycle of your furnace. The following chart offers estimated oil consumption during specific outside temperatures.


Outside Temperature (°F)Gallons Of Oil Used In 24 Hour Period*

*assumes a well-insulated house with an average size of 1,800 square feet; assumes oil tank and furnace are well maintained and in good condition

How Long Should 100 Gallons of Heating Oil Last?

Let’s say average outside temperatures are around 40 degrees F. A 100-gallon tank providing heat at 17 gallons per day will last 5.8 days (about 6 days).

But remember, there are a lot of variables that impact the efficiency of your home heating system and how long those 100 gallons last. For example, variables can include home size, tank size, home insulation, number of residents, outdoor temperatures, and your level of comfort.

Want all this to be worry-free? Opt for Young’s Automatic Oil Delivery. We will estimate your oil usage based on our “degree day” system, which factors in variables as well as your past usage to project how many days your oil supplies will last and determine your next automatic oil delivery.

How Long Will 1/8 Tank of Heating Oil Last?

Typical home oil tanks will fill to 245 gallons, so 1/8 tank will supply about 31 gallons of oil.  At 40 degrees F outside temperature, 1/8 tank will last you 2-4 days ( your furnace won’t likely be running 100% of that time and, again, there are many variables involved).

How About 1/4 Tank?

With a standard residential, 275-gallon oil tank, filled to 245 gallons (leaving air space for the oil to expand), a quarter-tank may last 4-6 days.  The chart above is a good reference for oil consumption per seasonal temperatures. But again, the size of your home, the number of occupants, the preference of indoor temperature, and other factors will play a role in how long 1/4 tank of heating oil lasts for you.

How Much Heating Oil Will I Use Per Day?

For an “average size” home of 1,650 square feet, you can estimate that you’ll use about 5 gallons of fuel oil per day to keep your home heated through Pennsylvania’s cold months. If your home has an older heating oil system, it won’t work as efficiently. Other variables mentioned previously will also play a role in how much heating oil you’ll use per day.

Our Automatic Oil Delivery is the best way to ensure your oil supplies are sufficient and available any day you need it.