Official chart library

Heating-oil tank charts: verified inches-to-gallons tables

Use manufacturer-published oil tank charts for a confirmed model and orientation. This library separates verified tables from calculated generic geometry and sends 275-gallon intent to its single canonical chart.

Open verified charts

Field notes

Choose the chart by label, not capacity alone

01
Match the manufacturer, model, nominal capacity, dimensions, and orientation before reading any gallons column.
02
The 138- and 330-gallon vertical tables below reproduce reviewed manufacturer chart points; they are not linear capacity estimates.
03
The verified 275-gallon vertical table lives only on the 275-gallon field guide so the same chart is not duplicated across URLs.
04
A horizontal tank, double-wall tank, or unidentified tank needs its own supported chart. Do not rotate or substitute a vertical table.

Official tank chart index

Verified residential oil tank charts

Each table has one manufacturer model and orientation. For the common 275-gallon vertical chart, use the dedicated field guide instead of a copied table.

330-gallon chart

Granby 205201P Standard 20Plus inches to gallons

Granby 205201P Standard 20Plus 72 x 27 x 44 in / vertical Official chart verified 2026-08-01

Granby 205201P Standard 20Plus 330-gallon vertical oil tank chart
Liquid depth	Gallons
0 in	0.0 gal
1 in	2.1 gal
2 in	6.0 gal
3 in	10.8 gal
4 in	16.5 gal
5 in	22.8 gal
6 in	30.2 gal
7 in	37.5 gal
8 in	45.2 gal
9 in	53.2 gal
10 in	61.4 gal
11 in	69.8 gal
12 in	78.3 gal
13 in	86.9 gal
14 in	95.5 gal
15 in	104.1 gal
16 in	112.7 gal
17 in	121.3 gal
18 in	129.9 gal
19 in	138.5 gal
20 in	147.1 gal
21 in	155.7 gal
22 in	164.3 gal
23 in	172.9 gal
24 in	181.5 gal
25 in	190.1 gal
26 in	198.7 gal
27 in	207.3 gal
28 in	215.9 gal
29 in	224.5 gal
30 in	233.1 gal
31 in	241.7 gal
32 in	250.3 gal
33 in	258.8 gal
34 in	267.2 gal
35 in	275.4 gal
36 in	283.4 gal
37 in	291.1 gal
38 in	298.4 gal
39 in	305.3 gal
40 in	311.7 gal
41 in	317.5 gal
42 in	322.5 gal
43 in	326.4 gal
44 in	328.6 gal

Manufacturer-stated chart precision is approximately +/-2%. Tank tilt, reading method, and installation add uncertainty. This table is planning information, not a delivery-meter reading.

138-gallon chart

Granby 208101 Standard inches to gallons

Granby 208101 Standard 30 x 27 x 44 in / vertical Official chart verified 2026-08-01

Granby 208101 Standard 138-gallon vertical oil tank chart
Liquid depth	Gallons
0 in	0.0 gal
1 in	0.9 gal
2 in	2.5 gal
3 in	4.5 gal
4 in	6.9 gal
5 in	9.5 gal
6 in	12.6 gal
7 in	15.6 gal
8 in	18.8 gal
9 in	22.2 gal
10 in	25.6 gal
11 in	29.1 gal
12 in	32.6 gal
13 in	36.2 gal
14 in	39.8 gal
15 in	43.4 gal
16 in	47.0 gal
17 in	50.5 gal
18 in	54.1 gal
19 in	57.7 gal
20 in	61.3 gal
21 in	64.9 gal
22 in	68.5 gal
23 in	72.0 gal
24 in	75.6 gal
25 in	79.2 gal
26 in	82.8 gal
27 in	86.4 gal
28 in	90.0 gal
29 in	93.5 gal
30 in	97.1 gal
31 in	100.7 gal
32 in	104.3 gal
33 in	107.8 gal
34 in	111.3 gal
35 in	114.7 gal
36 in	118.1 gal
37 in	121.3 gal
38 in	124.3 gal
39 in	127.2 gal
40 in	129.9 gal
41 in	132.3 gal
42 in	134.4 gal
43 in	136.0 gal
44 in	136.9 gal

Manufacturer-stated chart precision is approximately +/-2%. Tank tilt, reading method, and installation add uncertainty. This table is planning information, not a delivery-meter reading.

Calculate between chart rowsUse the calculator only after the label and orientation match one of its reviewed charts.

Route-specific question

One distinction that matters

Which heating-oil tank charts are included here?

This page publishes the verified Granby 138- and 330-gallon vertical tables. The verified Granby 275-gallon vertical table remains on the 275-gallon field guide and is linked from this library.

Can I use a chart when I only know the tank capacity?

No. Tanks with the same nominal capacity can have different bodies and orientations. Confirm the manufacturer label, model, dimensions, and orientation before choosing a chart.

Are these gallons calculated from generic tank geometry?

No. The published rows come from the cited manufacturer capacity chart. The separate capacity calculator is clearly labeled as a geometry-based estimate for unidentified tanks.

Source boundary

Official source material

Model values require manufacturer support; safety and removal guidance uses official public-agency material. Verification date: 2026-08-02.

Granby Standard 20Plus residential oil tanks
Manufacturer model dimensions and orientation; verified 2026-08-01.
Granby U.S. vertical tank capacity chart
Manufacturer gallons-by-inch table, stated precision +/-2%; verified 2026-08-01.
Roth double-wall heating-oil tanks
Manufacturer nominal capacities and body dimensions; verified 2026-08-01.

Continue the route

Use the next tool only when the job changes.

03 / VerifyCheck a 275-gallon tankResolve the most common nominal size without assuming one body shape.05 / GaugeCalculate a gauge readingTurn a fraction or stick depth into chart-based gallons.02 / CompareCompare sizesUse one verified model table shared by every tool.