Oil Tank Standard Sizes & What Size I Need

Standard home heating oil tank sizes are 100 to 1000 gallons. Most homes use 300 to 500 gallon tanks depending on their annual oil use, how much room they have for the tank and how often they are willing to have their tank filled.

This page has a wide range of information about residential tanks including an oil tank size chart for all common heating oil tank sizes and their dimensions. You will know what size tank you have or what size will fit the location you plan to place it.

Heating Oil Tank Sizes

Home heating oil tank manufacturers make small oil tank sizes starting at 100 gallons to large tanks that are usually placed outside and often buried.

The most common sizes for residential tanks are 275, 330, 500 and 550. Tanks that hold 1000 gallons are often used for multi-family homes or commercial buildings.

Oil Tank Size Chart

275 Gallon VerticalL x W x H: 60”x44”x27”Gallons
275 Gallon HorizontalL x W x H: 60”x27”x44”250 Gallons
330 Gallon VerticalL x W x H: 72”x27”x44”300 Gallons
330 Gallon HorizontalL x W x H: 72”x44”x27”300 Gallons
500 Gallon CylinderL x Diameter: 65”x48”450 Gallons
550 GallonL x Diameter: 72”x48”500 Gallons
1000 GallonL x Diameter: 130”x48”900 Gallons

How big is a 275-gallon oil tank?

60”x44”x27” or 60”x27”x44”.

Those measurements are L x W x H.

Chart note: Small oil tank sizes like 100, 105, 120, 150, 230 and 250 gallon tanks are not standard. In other words, there are no industry-accepted dimensions for them. Most home heating oil companies do not offer them because they run out more quickly, and the companies don’t want the expense of making a lot of trips to your home – and they don’t want the frequent emergency calls when homeowners run out unexpectedly.

Oil Tank Dimensions

Dimensions vary slightly by manufacturer.

The oil tank size chart above provides the sizes with dimensions. If you want to answer, “how much oil does my tank hold?”, you can measure your tank and compare it to our chart for the answer.

Horizontal Tanks Dimensions
Horizontal Tanks Dimensions
Vertical Tanks Dimensions
Vertical Tanks Dimensions

Concerning dimensions:

  • Horizontal tanks are significantly longer than they are tall.
  • Vertical tanks are taller than horizontal tanks, but they are still wider than they are tall.
  • Cylinders are round, so the dimensions are length and diameter.

These are the terms the industry has adopted to describe heating oil tank sizes and dimensions.  

What Size Tank Do I Need?

The most common sizes for residential homes are 275 to 500 gallons.

While there is no hard-and-fast rule, this chart shows the most common sizes.

BedroomsTank Size
1-2275 or 330 Gallons
3-4500 or 550 Gallons
5+ Large home or duplex500, 550 or 1000 Gallons

What size tank for a 3 bedroom home?

500 or 550 gallons, especially if you live in a climate where winters are long and very cold.

What size tank for a 2 bedroom home?

A 275 gallon or 330 gallon tank is the right size tank.

How Much Oil Is In My Tank?

If you know the size of your tank and its dimensions, the depth of the oil in it will tell you how many gallons of oil are left. 

This is a common question and one that is fairly easy to answer. 

How to Measure the Oil in the Tank

What you’ll need is a clean measuring stick – a metal tape isn’t the best choice because it can flex and give a false reading plus heating oil is a mess to clean off a tape. So, an old yardstick will work, or you can use a clean 1”x1” or 1”x2” board or a 1” dowel.

Tip: Make sure your measuring stick is at least 6” (12” is better) taller than the tank, so you can easily keep a grip on it while measuring. You certainly don’t want the stick falling into the tank!

Now, to find out how much fuel oil is in the tank, remove the cap, and push your measuring rod straight down to the bottom. Slowly remove the rod, and you might want to use a paper towel or a shop rag to wipe off the excess oil as it comes out.

Next, measure the “wet” part of the rod to determine how many inches of oil are in the tank.

This chart answers the question, “how much heating oil is left in my tank?” It is in increments of 4 inches. There are charts available online that show how much oil is in the tank for every inch up to full.

A 275H tank is a horizontal tank holding 275 gallons. H=Horizontal; V=Vertical. 550 and 1000 gallon tanks are cylinders. See the Oil Tank Size Chart above for details on dimensions, so you will know what size tank you have.

Inch to Gallon Oil Tank Chart

Inches From Bottom275H (gal.)275V (gal.)330H (gal.)330V (gal.)550 (gal.)1000 (gal.)
28”N/A 179N/A211334606

How much oil is 12”?

65 gallons to 196 gallons depending on the size and dimensions of your tank. See the chart above for details.

How much oil is 28 inches in a 550 gallon tank?

334 gallons.

Those examples are given to demonstrate how to use the Inches to Gallon Oil Tank Chart.

Here’s an example of how to do it. Notice that the oil is dripping on the ground because he doesn’t clean it off as it comes out! That’s another reason to use a wood dowel. You can wipe it, and it will still be wet where the oil touched.

Home Heating Oil Tank Sizes

Here are the most common heating oil tank sizes residential use:  

275 Gallons

This is a popular size for most homes, especially those with 1-2 bedrooms. If you have a 3-bedroom home but only 1 or 2 people in the household, this size should be OK for you.

The vertical size, 60”Lx27”Wx44”H, is used more often because it has a smaller footprint than the horizontal size. If you have a crawlspace, consider the horizontal tank, which has a lower profile at just 27” high.

330 Gallons

This size is best for homes with 2 or 3 bedrooms and a household of 2 or 3 people. They come in vertical tanks with a smaller footprint and horizontal tanks which are better for crawlspaces. They are 12” longer than 275 gallon oil tanks. Tip: If your climate is very cold, consider a 550-gallon tank.

550 Gallons

Ideal for 3-bedroom homes with 4+ people in the home, 550 gallon tanks are cylinders, meaning they are nearly round. That’s why the dimensions are given in height x diameter. Most 550G tanks are set above ground outside. Some companies might bury 550G tanks.

1000 Gallons

Tanks this size are usually buried because they take up quite a lot of room at 130” long with a diameter of 48”. It is “impossible” to get them into most homes. You might have an option on where to locate it. 1000 gallon tanks are suitable for duplexes and very large homes with 5+ people living in them.


What is the standard oil tank size?

275 gallons or 330 gallons.

These are the most common sizes and are considered standard.

How much oil does my tank hold?

Your fuel oil company won’t fill the tank to capacity. Normally, they like to fill it to about 90% capacity to allow for expansion of the oil in hot weather.

A 275 gallon tank has a capacity of about 250 gallons. 330G tanks are full at about 300 gallons. 500G tanks are filled to 450 gallons, and 550G tanks are filled to about 500 gallons. A 1000 gallon tank is usually considered “full” at 900 gallons.

How can I measure my oil tank?

Measure length x width x height. For a cylinder, measure length x diameter.

A common question is – What size is my heating oil tank?

Here are the details for how to determine oil tank size.

Measure a horizontal or vertical tank by:

1 – Measuring the length

2 – Measuring the height at the tallest part

3 – Measuring the width at the widest part

Measure a cylinder by:

1 – Measuring the length

2 – Measuring the diameter – all the way around the tank – using a flexible tape measure

What are basement heating oil tank sizes?

275 gallons and 330 gallons.

Larger tanks don’t fit through most doorways into the basement.

What small oil tank sizes are available?

100, 20, 138, 220, 230 and 240 gallons, but it varies by location. Small home fuel oil tank sizes from 100 to 220 gallons are rare, however.

What is the warranty on a home heating oil tank?

Warranties are 10 years, 20 years, 25 years or 30 years depending on the construction and size of the tank.

Non-coated single-wall tanks have 10-year warranties. If the tank is coated with polyurethane and/or has a double bottom, the warranty will be 20 to 30 years.

Did you know? Some HVAC and home heating fuel suppliers offer a special warranty on your residential heating oil tank if you sign up to have a corrosion inhibitor added to your fuel oil. It’s typically available only for above-ground tanks.

How long does an oil tank last?

Tank lifespan is 20 to 35 years. It depends on the construction, whether it is coated and whether it’s inside or outside.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.
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