330 gallon vertical oil tank chart
The 330 vertical is the 275's longer sibling: the same 27″ wide, 44″ tall oval end, stretched from 60 to 72 inches. Plenty of basements hold one without the owner knowing, because from the end the two tanks look identical. Stick it through the fill or gauge opening, read the wet line, and convert below.
gallons % of a full 330 gallon vertical tank
Enter a reading to convert it, fill the tank pictures, and highlight your row in the chart below.
| Inches | Gallons | Inches | Gallons |
|---|---|---|---|
| 1″ | 2 | 23″ | 173 |
| 2″ | 6 | 24″ | 182 |
| 3″ | 11 | 25″ | 190 |
| 4″ | 17 | 26″ | 199 |
| 5″ | 23 | 27″ | 207 |
| 6″ | 30 | 28″ | 216 |
| 7″ | 38 | 29″ | 225 |
| 8″ | 45 | 30″ | 233 |
| 9″ | 53 | 31″ | 242 |
| 10″ | 61 | 32″ | 250 |
| 11″ | 70 | 33″ | 259 |
| 12″ | 78 | 34″ | 267 |
| 13″ | 87 | 35″ | 275 |
| 14″ | 95 | 36″ | 283 |
| 15″ | 104 | 37″ | 291 |
| 16″ | 113 | 38″ | 298 |
| 17″ | 121 | 39″ | 305 |
| 18″ | 130 | 40″ | 312 |
| 19″ | 138 | 41″ | 318 |
| 20″ | 147 | 42″ | 322 |
| 21″ | 156 | 43″ | 326 |
| 22″ | 164 | 44″ | 329 |
Generated 2026-06-12. Computed from nominal tank geometry at 231 cubic inches per gallon, with a 2.2 percent dished-head allowance calibrated to the manufacturer’s published capacity chart. Matches the chart books oil dealers use within about a gallon.
Reading the numbers
- Full is about 329 gallons. A normal fill stops a few inches short of the top anyway.
- Half is 22 inches, 164 gallons. A quarter (about 82 gallons) sits near 13 inches, a sensible reorder point once the weather turns.
- The middle of the tank moves about 8.6 gallons per inch, against just over 7 for a 275 vertical. The extra foot of length shows up in every inch.
- At 10 inches you are down to about 61 gallons. In a cold snap that is days of heat, not weeks.
- Identify the tank before you trust the chart. A 330 read with a 275 chart comes out about 20 percent low. If your tank measures 72 inches end to end, this is your chart.
Common questions
How do I tell a 330 vertical from a 275 vertical?
You cannot from the end: both are 27 inches wide and 44 inches tall. Measure the length. 60 inches is a 275, 72 inches is a 330. The data plate on the tank end settles it, if the stamping is still readable.
What happens if I use the 275 chart by mistake?
Every reading comes out about 20 percent low. At 20 inches the 275 vertical chart says about 123 gallons, while this tank actually holds about 147 at the same depth. A wrong-chart reading is a common reason the run-out math never adds up.
Why is full 329 instead of 330?
About 329 gallons is what the tank geometry computes to with its dished heads; the 330 label rounds up the last gallon. A real fill lands lower, because the delivery whistle stops the fill below the top to leave an air gap.
When should I reorder?
In winter, do not ride below a quarter tank: about 82 gallons, around 13 inches on the stick. That leaves room for a delivery to be a few days out. See when to order heating oil.
Related
- 275 gallon vertical chart (the shorter sibling)
- 330 gallon horizontal chart (same tank lying flat)
- What size is my oil tank?
- How to stick an oil tank