Inches to gallons for every common heating oil tank

330 gallon vertical oil tank chart

The 330 vertical is the tall oval that measures 27″ wide, 44″ tall and a full 72″ long. Plenty of basements hold one without the owner knowing, because from the end it looks identical to the shorter oval that shares its 27 by 44 inch face. Stick it through the fill or gauge opening, read the wet line, and convert below.

330 gallon vertical
130 gallons in the tank

Type a reading, or drag the level

330 gallon vertical oil tank conversion chart, inches of oil to gallons
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 2026-07-27. 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

Common questions

How do I know my tank is a 330 and not a smaller oval?

You cannot tell from the end, because the common upright ovals share the same 27 inch by 44 inch face. Measure the length instead: 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 read this tank with the wrong chart?

Every reading comes out about 20 percent low. At 20 inches a chart for the 60 inch oval 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.

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