How much oil is left in my tank?

That’s a common question that can be answered in two ways:

How many inches of oil are left in the tank?

What does the gauge read?

This page has exact answers to the question whichever way you measure how much heating oil remains in the tank.

## Oil Tank Fullness Calculator

It’s simple to use. Try it out, and if you need directions, they are found below the oil tank fill calculator.

**Oil Tank Measuring Calculator**

**1 –** Choose your tank type – they are explained below

**2 –** Choose your Measuring Method

**3 –** Select the Fraction on the gauge, if using that method, or the number of inches in the tank using the slide bar if measuring that way

**4 –** Hit Calculator, and your Current Oil Amount and Oil Needed to Fill are shown.

*Current Oil Amount and Oil Needed to Fill don’t add up to tank capacity!!!*

That’s right. They should add up to around 87% to 90%, which is the percentage most heating oil companies will fill your tank.

**Oil Tank Measuring by Chart and Gauge**

Below, you will find oil fullness charts based on what the gauge says and by how many inches of heating oil is left.

Charts for tank sizes 275 gallons, 330 gallons, 500 gallons, 550 gallons and 1000 gallons are available – and separate tanks for horizontal and vertical tanks are produced for applicable tank sizes.

## Oil Tank Measuring Chart by Gauge

**My gauge reads ¼. How much oil is in my tank?**

Questions like that are common. And you have to know your tank capacity to do the math. But the math is done for you in our Current Oil Amount Measuring Chart and our Current Oil Amount Needed for Max Fill Chart.

They tell you how much is in the tank and how much can be filled to the point of maximum capacity. All common oil tank sizes are included.

### Current Oil Amount Measuring Chart

Oil Tank Size | Current Oil (Gauge: 1/4) | Current Amount (Gauge: 1/2) | Current Amount (Gauge: 3/4) |

275 Tank | 69 gallons | 138 gallons | 206 gallons |

330 Tank | 83 gallons | 165 gallons | 248 gallons |

500 Tank | 125 gallons | 250 gallons | 375 gallons |

550 Tank | 138 gallons | 275 gallons | 413 gallons |

1000 Tank | 250 gallons | 500 gallons | 750 gallons |

**How much oil is in my 275 gallon tank when the gauge is ¼?**

69 gallons. Find 275 in the left column, the Oil Tank Size column. Then move to the right one column to the Current Oil (Gauge: 1/4) column, and you’ll see it says 69 gallons.

That’s how the chart works.

### Current Oil Amount Need For Max Fill Chart

Oil Tank Size | Current Oil (Gauge: 0) | Current Oil (Gauge: 1/4) | Current Amount (Gauge: 1/2) | Current Amount (Gauge: 3/4) |

275 Tank | 240 gallons | 171 gallons | 102 gallons | 34 gallons |

330 Tank | 300 gallons | 217 gallons | 165 gallons | 52 gallons |

500 Tank | 450 gallons | 325 gallons | 200 gallons | 75 gallons |

550 Tank | 500 gallons | 362 gallons | 225 gallons | 87 gallons |

1000 Tank | 900 gallons | 650 gallons | 400 gallons | 150 gallons |

**My 500 gallon tank is empty. How many gallons to fill it?**

450 gallons can be put in the tank to bring it to maximum capacity of 90%.

**My 275 gallon take gauge is 1/2. How many gallons to fill it?**

About 102. A half-full 275 gallon tank has about 138 gallons and can have a max fill of about 240 gallons, so it can take another 102 gallons.

And that is how that chart works!

## Oil Tank Measuring Chart by Inches

The charts below cover all common tank sizes: 275, 330, 500, 550 and 1000 gallons in horizontal and vertical where applicable.

**How to Measure Oil in the Tank:** To use these charts, you obviously need to know the amount, in inches, of oil in the tank. We recommend a **clean** wood or metal measuring stick – but not a tape measure, since they’re harder to clean, and you might not want home heating oil residue gumming up your tape.

Either put inch markings on the stick or use a stick without markings, measure the oil, wipe off the stick, and measure the wet area.

**Tip:** Push the measuring rod straight down in the middle of the tank for the most accurate reading. A slanted measure will give you an inaccurate reading – you’ll think there is more oil in the tank than there is.

## 275 Gallon Oil Tank Chart (Horizontal)

Horizontal 275 gallon tanks are among the most popular.

How much oil is in my 275 gallon tank?

This chart makes it easy to tell both how much is left and how much you can put into it to bring it to 90% max capacity.

### 275 gallon oil tank chart (horizontal)

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 6 | 235 |

2″ | 14 | 225 |

3″ | 22 | 220 |

4″ | 31 | 210 |

5″ | 41 | 200 |

6″ | 52 | 185 |

7″ | 63 | 175 |

8″ | 74 | 165 |

9″ | 85 | 155 |

10″ | 96 | 145 |

11″ | 108 | 130 |

12″ | 119 | 120 |

13″ | 131 | 110 |

14″ | 143 | 95 |

15″ | 154 | 85 |

16″ | 166 | 75 |

17″ | 178 | 60 |

18″ | 189 | 50 |

19″ | 199 | 40 |

20″ | 211 | 30 |

21″ | 222 | 20 |

22″ | 232 | 10 |

23″ | 240 | 0 |

24″ | 251 | 0 |

25″ | 260 | 0 |

26″ | 268 | 0 |

27″ | 275 | 0 |

**There is 12” of oil in my tank. How much oil is left?**

In a 275 gallon horizontal tank, there are about 119 gallons left. And if you want it full, order 120 gallons.

## 275 Gallon Oil Tank Chart (Vertical)

This chart works exactly the same. Since it is a vertical tank (60” long, 44” high and 27” wide), there is less oil per inch than in a horizontal 275 gallon tank.

### 275 gallon oil tank chart (vertical)

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 2 | 250 |

2″ | 5 | 245 |

3″ | 9 | 240 |

4″ | 14 | 235 |

5″ | 19 | 230 |

6″ | 25 | 225 |

7″ | 31 | 215 |

8″ | 37 | 210 |

9″ | 44 | 205 |

10″ | 51 | 195 |

11″ | 58 | 190 |

12″ | 65 | 185 |

13″ | 72 | 180 |

14″ | 80 | 170 |

15″ | 87 | 160 |

16″ | 94 | 155 |

17″ | 101 | 145 |

18″ | 108 | 140 |

19″ | 115 | 135 |

20″ | 123 | 125 |

21″ | 130 | 120 |

22″ | 137 | 110 |

23″ | 144 | 105 |

24″ | 151 | 95 |

25″ | 158 | 90 |

26″ | 166 | 80 |

27″ | 173 | 75 |

28″ | 180 | 70 |

29″ | 187 | 60 |

30″ | 194 | 55 |

31″ | 201 | 45 |

32″ | 209 | 40 |

33″ | 216 | 30 |

34″ | 223 | 25 |

35″ | 230 | 20 |

36″ | 236 | 15 |

37″ | 243 | 5 |

38″ | 249 | 0 |

39″ | 254 | 0 |

40″ | 260 | 0 |

41″ | 265 | 0 |

42″ | 269 | 0 |

43″ | 272 | 0 |

44″ | 275 | 0 |

## 330 Gallon Oil Tank Chart (Horizontal)

330G heating oil tanks are pretty common too. If you’re not sure what size tank you have, it might indicate the size on the tank or on an invoice from the tank supplier. Contact them, if you still need the size info.

### 330 Gallon Oil Tank Chart (Horizontal)

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 7 | 290 |

2″ | 17 | 280 |

3″ | 27 | 270 |

4″ | 38 | 260 |

5″ | 49 | 250 |

6″ | 63 | 235 |

7″ | 75 | 225 |

8″ | 89 | 210 |

9″ | 102 | 195 |

10″ | 116 | 180 |

11″ | 129 | 170 |

12″ | 143 | 155 |

13″ | 157 | 140 |

14″ | 171 | 125 |

15″ | 185 | 115 |

16″ | 199 | 100 |

17″ | 213 | 85 |

18″ | 227 | 70 |

19″ | 238 | 60 |

20″ | 253 | 45 |

21″ | 266 | 30 |

22″ | 278 | 20 |

23″ | 287 | 15 |

24″ | 301 | 0 |

25″ | 312 | 0 |

26″ | 321 | 0 |

27″ | 330 | 0 |

**There are 10” left in my oil tank. How much oil is 10”?**

116 gallons in a 330 gallon horizontal tank.

Find the number of inches in the left column. The center column shows approx. how much oil remains. The right column shows how much can be added to fill the tank to 90% full.

**What are horizontal 330 gallon oil tank dimensions?**

The size of most 330 gallon horizontal tanks is L x W x H: 72”x44”x27”

## 330 Gallon Oil Tank Chart (Vertical)

This chart is simple to use. After measuring the amount of oil in the tank, find the number of inches in the left column.

The current amount in gallons is shown in the middle column. The right column shows how many gallons are needed to fill it to 90%.

### 330 Gallon Oil Tank Chart (Vertical)

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 2 | 300 |

2″ | 6 | 295 |

3″ | 11 | 285 |

4″ | 17 | 280 |

5″ | 23 | 275 |

6″ | 30 | 270 |

7″ | 38 | 260 |

8″ | 45 | 255 |

9″ | 53 | 245 |

10″ | 61 | 235 |

11″ | 70 | 230 |

12″ | 78 | 220 |

13″ | 87 | 210 |

14″ | 96 | 205 |

15″ | 104 | 195 |

16″ | 113 | 185 |

17″ | 121 | 175 |

18″ | 130 | 170 |

19″ | 139 | 160 |

20″ | 147 | 150 |

21″ | 156 | 145 |

22″ | 164 | 135 |

23″ | 173 | 125 |

24″ | 182 | 115 |

25″ | 190 | 110 |

26″ | 199 | 100 |

27″ | 207 | 90 |

28″ | 216 | 85 |

29″ | 225 | 75 |

30″ | 233 | 65 |

31″ | 242 | 55 |

32″ | 250 | 50 |

33″ | 259 | 40 |

34″ | 267 | 30 |

35″ | 275 | 25 |

36″ | 283 | 15 |

37″ | 291 | 5 |

38″ | 298 | 0 |

39″ | 305 | 0 |

40″ | 312 | 0 |

41″ | 318 | 0 |

42″ | 323 | 0 |

43″ | 326 | 0 |

44″ | 330 | 0 |

**Note:** The size of most 330 gallon vertical tanks is L x W x H: 72”x27”x44”

## 500 Gallon Oil Tank Chart

A 500 gallon oil tank is a good choice for a 3-4 bedroom home. Typical dimensions are 65”x48”, and most tanks are cylinders.

How much oil is left in your tank?

This simple-to-use chart is quite accurate.

### 500 Gallon Oil Tank Chart

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 3 | 445 |

2″ | 7 | 440 |

3″ | 13 | 435 |

4″ | 20 | 430 |

5″ | 28 | 420 |

6″ | 36 | 415 |

7″ | 45 | 405 |

8″ | 55 | 395 |

9″ | 65 | 385 |

10″ | 75 | 375 |

11″ | 86 | 365 |

12″ | 98 | 350 |

13″ | 109 | 340 |

14″ | 121 | 325 |

15″ | 133 | 315 |

16″ | 146 | 305 |

17″ | 158 | 290 |

18″ | 171 | 275 |

19″ | 184 | 265 |

20″ | 197 | 250 |

21″ | 210 | 240 |

22″ | 223 | 225 |

23″ | 237 | 210 |

24″ | 250 | 200 |

25″ | 263 | 185 |

26″ | 276 | 175 |

27″ | 290 | 160 |

28″ | 303 | 145 |

29″ | 316 | 135 |

30″ | 329 | 120 |

31″ | 341 | 105 |

32″ | 354 | 95 |

33″ | 366 | 85 |

34″ | 379 | 70 |

35″ | 390 | 60 |

36″ | 402 | 45 |

37″ | 413 | 35 |

38″ | 424 | 25 |

39″ | 435 | 15 |

40″ | 445 | 5 |

41″ | 455 | 0 |

42″ | 464 | 0 |

43″ | 472 | 0 |

44″ | 480 | 0 |

45″ | 487 | 0 |

46″ | 493 | 0 |

47″ | 497 | 0 |

48″ | 500 | 0 |

**How much oil is 12” in a 500 gallon tank?**

98 gallons. And there’s room for about 350 gallons more.

That’s how to use the chart. Find the right number in the Inches column, and use the center and right columns to show current amount and potential fill amount to bring it to maximum 90% capacity.

## 550 Gallon Oil Tank Chart

A 550 gallon tank is usually 72” long and 48” tall. It’s a cylinder.

### 550 Gallon Oil Tank Chart

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 3 | 495 |

2″ | 8 | 490 |

3″ | 14 | 485 |

4″ | 22 | 475 |

5″ | 30 | 470 |

6″ | 40 | 460 |

7″ | 50 | 450 |

8″ | 60 | 440 |

9″ | 71 | 425 |

10″ | 83 | 415 |

11″ | 95 | 405 |

12″ | 108 | 390 |

13″ | 120 | 380 |

14″ | 134 | 365 |

15″ | 147 | 350 |

16″ | 161 | 335 |

17″ | 174 | 325 |

18″ | 188 | 310 |

19″ | 203 | 285 |

20″ | 217 | 280 |

21″ | 231 | 265 |

22″ | 246 | 255 |

23″ | 261 | 235 |

24″ | 275 | 225 |

25″ | 290 | 210 |

26″ | 304 | 195 |

27″ | 319 | 180 |

28″ | 333 | 165 |

29″ | 348 | 115 |

30″ | 362 | 135 |

31″ | 376 | 125 |

32″ | 390 | 110 |

33″ | 403 | 95 |

34″ | 417 | 80 |

35″ | 430 | 70 |

36″ | 443 | 55 |

37″ | 455 | 45 |

38″ | 467 | 30 |

39″ | 479 | 20 |

40″ | 490 | 10 |

41″ | 501 | 0 |

42″ | 511 | 0 |

43″ | 520 | 0 |

44″ | 528 | 0 |

45″ | 536 | 0 |

46″ | 542 | 0 |

47″ | 548 | 0 |

48″ | 550 | 0 |

## 1000 Gallon Oil Tank Chart

1000 gallon oil tanks are cylinders. Most are about 130” long and 48” tall. They are often used in commercial rather than residential settings.

### 1000 Gallon Oil Tank Chart

Inches From Bottom | Current Amount (Gal.) | Amount Needed to Fill Tank(Gal.) |

1″ | 5 | 895 |

2″ | 14 | 885 |

3″ | 26 | 870 |

4″ | 40 | 860 |

5″ | 55 | 845 |

6″ | 72 | 825 |

7″ | 90 | 810 |

8″ | 110 | 790 |

9″ | 130 | 770 |

10″ | 151 | 745 |

11″ | 173 | 725 |

12″ | 195 | 705 |

13″ | 219 | 680 |

14″ | 243 | 655 |

15″ | 267 | 630 |

16″ | 292 | 605 |

17″ | 317 | 580 |

18″ | 342 | 555 |

19″ | 368 | 530 |

20″ | 394 | 505 |

21″ | 420 | 480 |

22″ | 447 | 450 |

23″ | 473 | 425 |

24″ | 500 | 400 |

25″ | 526 | 370 |

26″ | 553 | 345 |

27″ | 579 | 320 |

28″ | 605 | 295 |

29″ | 631 | 265 |

30″ | 657 | 240 |

31″ | 683 | 215 |

32″ | 708 | 190 |

33″ | 733 | 165 |

34″ | 757 | 140 |

35″ | 781 | 115 |

36″ | 804 | 95 |

37″ | 827 | 70 |

38″ | 849 | 50 |

39″ | 870 | 30 |

40″ | 890 | 10 |

41″ | 909 | 0 |

42″ | 927 | 0 |

43″ | 944 | 0 |

44″ | 960 | 0 |

45″ | 974 | 0 |

46″ | 985 | 0 |

47″ | 994 | 0 |

48″ | 1000 | 0 |

## FAQs

**What is the maximum capacity of an oil tank?**

90%. That’s the average. If you live in a very hot climate, though oil heating is rare there, your supplier might only want to fill the tank to 80% or 85%.

In a very cold climate, it’s possible that some suppliers might fill a tank to slightly above 90%.

This is because oil expands more in high temperatures.

**What is maximum oil tank capacity by size?**

At 85% to 90%, here are tank sizes and max fill capacity.

**275:**220 to 248 gallons**300:**255 to 270 gallons**330:**280 to 297 gallons**500:**425 to 450 gallons**550:**468 to 495 gallons**1000:**850 to 900 gallons

**When should I have my tank refilled?**

Most suppliers suggest ordering a fill when your tank gets to 1/4 if you have a gauge.

If you use a measuring stick, then you should order more oil when the tank is at about 15% to 20%. Use the charts above to determine how many inches that is for the tank size you have.

**My tank doesn’t have a gauge. Can I add one?**

Yes. Ask your oil supplier about adding a gauge, or consider adding your own ultrasonic gauge with WiFi for convenience.

**Oil Tanks – H or V?**

“H” is horizontal, and “V” is vertical.

However, even vertical tanks are wider than they are tall. Does that make sense?

For example, a 275 gallon tank is usually 60” long, regardless of whether it is horizontal or vertical.

Width and height are where the two differ.

**Horizontal:**27” high or tall, and 44” wide**Vertical:**Just the opposite – 44” high or tall, and 27” wide.

Similar differences are 330-gallon tanks and a few other sizes available in both vertical and horizontal options.