275 gallon horizontal oil tank chart
Same capacity as the standard 275 vertical, lying flat: 44″ wide, 27″ tall, 60″ long. Horizontals turn up in crawl spaces and low basements where a 44 inch tall tank will not fit. The stick only travels 27 inches here, so never read this tank against a vertical chart. Enter your wet-line inches below.
Type a reading, or drag the level ↕
| Inches | Gallons | Inches | Gallons |
|---|---|---|---|
| 1″ | 6 | 15″ | 154 |
| 2″ | 14 | 16″ | 166 |
| 3″ | 23 | 17″ | 178 |
| 4″ | 32 | 18″ | 189 |
| 5″ | 42 | 19″ | 200 |
| 6″ | 52 | 20″ | 211 |
| 7″ | 63 | 21″ | 222 |
| 8″ | 74 | 22″ | 232 |
| 9″ | 85 | 23″ | 242 |
| 10″ | 96 | 24″ | 251 |
| 11″ | 108 | 25″ | 260 |
| 12″ | 119 | 26″ | 267 |
| 13″ | 131 | 27″ | 274 |
| 14″ | 143 |
Tap any row to send that reading to the gauge above.
Generated 2026-09-20. 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.
Preview the printable sheet
Reading the numbers
- Full is about 274 gallons, the same oil as a 275 vertical. A normal delivery stops a few inches below the top to leave an air gap.
- Half is 13.5 inches, about 137 gallons. On the upright 275 the half mark sits at 22 inches, so check which way your tank sits before you read either chart.
- The middle band moves about 11.7 gallons per inch, versus just over 7 on the vertical. Lying down, the oil sits shallower and wider, so each inch of depth covers more of it.
- A quarter tank (about 69 gallons) sits at about 8 inches. Treat that as your winter reorder line.
- At 5 inches you are down to about 42 gallons. Schedule a delivery now, not after the weekend.
Common questions
Is my 275 horizontal or vertical?
Look at the oval end. If it lies wider than tall (44″ wide, 27″ high), it is horizontal and this chart applies. If the oval stands taller than it is wide, use the 275 vertical chart.
Why are the inches so different from the 275 vertical chart?
Both tanks hold about 274 gallons, but this one spreads the oil over 27 inches of depth instead of 44. On the vertical chart, 13 inches is about 72 gallons, a quarter tank. Here, 13.5 inches is 137 gallons, an honest half.
How many gallons is one inch of oil?
About 11.7 gallons at mid height, where the rounded ends are at their full spread. Nearer the top and the bottom the oil surface narrows and an inch is worth under 8, so use the chart rather than multiplying inches by a single figure.
Why did my "full" tank take less than 274 gallons?
The fill whistle stops the driver a few inches below the top, and a little oil below the outlet never gets burned. Nominal size, computed full, and a real-world fill are three different numbers. The arithmetic is in why a 275 holds about 240.
Related
- 275 gallon vertical chart (same tank stood on end)
- 330 gallon horizontal chart (same height, 12 inches longer)
- How to stick an oil tank
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