Heating Oil Tank Size Chart: Dimensions, Capacities and Inch-to-Gallon Data

What are the key heating oil tank size chart statistics?

These figures lead with the numbers most likely to be needed in a deadline-driven lookup. Each line is self-contained, names its source and carries the July 27, 2026 verification date.

What does the heating oil tank size chart show by model?

Nominal capacity does not identify a tank. Across the 55 manufacturer-documented records, 22 distinct nominal capacities appear in different shapes and orientations, so manufacturer, construction, model and orientation must be matched before a conversion chart applies.

Dimensions are shown in the order the manufacturer publishes them. Where a source gives height, width and length, the table keeps that order rather than silently reordering the figures.

Steel obround tanks

"Obround" means a rectangle capped with semicircular ends — the flattened oval seen on the end of many basement tanks. UL 80 permits obround construction, and that changing cross-section is why gallons per inch is not a straight line.

Table 1. Steel obround heating-oil tank dimensions

Source: Granby Industries, Standard Residential Oil Storage Tank UL-80 product page and June 2026 residential-tank brochure; Highland Tank, Tank Gauge Charts HT-6000-01/2021. Retrieved July 27, 2026. Highland's chart book does not state a listing for these basement models.

Double-wall and nonmetallic tanks

These models carry manufacturer listings to UL SU 2258 or UL/ULC 2258 rather than UL 80. They also show why a nominal 275-gallon label does not predict shape or headroom.

Table 2. Double-wall and nonmetallic tank dimensions

Source: Roth North America, EcoDWT plus 3 Installation Instructions; Granby Industries, June 2026 residential-tank brochure and 2-in-1 product material. Retrieved July 27, 2026.

The minimum-height column is the one that catches people out. A Roth 1000L carries the same nominal 275-gallon label as a steel basement tank but requires 66 inches of installed height, while the low-profile 1000LH requires 60 inches.

Fiberglass tanks

Granby's two official brochures checked in this audit do not present an identical fiberglass lineup. The table uses the June 12, 2026 brochure for current values and labels rows that appear only in the official May 20, 2025 brochure.

Table 3. Granby fiberglass tank dimensions and source status

Source: Granby Industries official residential-tank brochures, revisions 06/12/26 and 05/20/25. Retrieved July 27, 2026. The D202 conflict is preserved in the source-integrity audit rather than reconciled silently.

Granby publishes separate capacity charts for some vertical fiberglass models. Those chart rows are outside the released 396-row chart CSV and are not reproduced on this page; a standard steel chart should not be substituted for a fiberglass model.

Highland Tank bench-top tanks

These four records are included so the visible tables account for all 55 model or configuration rows in the downloadable dimensions dataset. Highland's chart book supplies the dimensions but does not state a listing in the table used here.

Table 4. Highland Tank bench-top dimensions

Source: Highland Tank, Tank Gauge Charts HT-6000-01/2021. Retrieved July 27, 2026.

Cylindrical and larger tanks

A nominal gallon number does not identify a cylindrical geometry either. The same nominal size can be assigned to different diameter-and-length combinations.

Table 5. Cylindrical and larger tank dimensions

Source: Granby Industries, June 2026 residential-tank brochure; Highland Tank, Tank Gauge Charts HT-6000-01/2021. Retrieved July 27, 2026.

A nominal 500-gallon Granby cylinder appears in two geometries: 46 inches in diameter by 72 inches long and 50 inches in diameter by 60 inches long. Highland likewise publishes two 1,000-gallon horizontal geometries, so diameter alone does not identify the model.

Why does one 275-gallon label cover six footprints?

The label is a nominal product designation, not a complete model identifier. These six dimension sets are all supported by the manufacturer documents in this release.

Table 6. Six manufacturer-documented 275-gallon footprints

Source: Granby Industries, Highland Tank and Roth North America manufacturer documents listed in the Sources section. Retrieved July 27, 2026.

Six footprints, one number. The tallest is 61 inches; the shortest is 27. The longest is 60 inches; the shortest is 43. They do not share one conversion chart and they do not fit the same spaces.

How do you tell what size heating oil tank you have?

The tank's data plate is the most direct identifier because it can supply the manufacturer, model or product number and nominal capacity. Where the plate is missing or illegible, exterior shape and all available dimensions can narrow the family, but they do not justify applying a chart whose model and orientation have not been matched.

What distinguishes tanks, in order of usefulness:

1. The data plate. Record the manufacturer, model or product number and nominal capacity. Those fields are more specific than a generic "275-gallon" label.
2. The end profile. A flattened oval taller than it is wide is a vertical obround; wider than tall is a horizontal obround. A flat-sided double-wall tank and a true cylinder require different reference data.
3. All three exterior dimensions. A 60-inch length alone does not settle the model. Height, width and length together can distinguish a 44 × 27 × 60-inch vertical obround from a 27 × 44 × 60-inch horizontal one and from the Roth rectangular configurations.
4. Documented delivery history as corroboration only. A past delivery can show that the tank held at least that much available volume at the time, but it does not establish the tank's nominal or maximum capacity.

Tank interiors, fill openings, vent lines and buried equipment are handled by qualified heating or tank professionals. Nothing on this page is a procedure for opening, probing, entering, cutting, disconnecting or otherwise working on a tank.

What do the published inch-to-gallon charts show?

A gallons-per-inch chart belongs to a specific tank shape, orientation and chart family. The tables below preserve manufacturer values, distinguish selected page rows from the released CSV's complete series and keep source conflicts visible rather than forcing unlike documents into one number.

Granby vertical tanks

Table 7. Granby vertical-tank gallons by liquid depth

Source: Granby Industries, "Capacity Chart for Vertical Tanks," retrieved July 27, 2026. Granby states that precision is about ±2% and that the chart is not intended for purchases or sales of products. The page table shows selected rows; the released 396-row CSV contains complete one-inch Granby series for 138, 220, 230, 275 and 330 gallons, not the 120- or 240-gallon columns shown here directly from the source PDF.

The 230-gallon column has no matching model in Granby's current U.S. Standard product lineup. At the final published row, four of the seven columns finish below nominal — 138, 220, 275 and 330 — while the 120 and 240 columns continue beyond 44 inches to 123 and 245 gallons.

Highland Tank basement tanks

Table 8. Highland Tank vertical basement-tank gallons by liquid depth

Source: Highland Tank, "Tank Gauge Charts," HT-6000-01/2021, retrieved July 27, 2026. The page table shows selected even-numbered rows; the released CSV contains the complete 44-row vertical series for 137, 230, 275 and 330 gallons. Highland's separate horizontal tables are not included in the 396-row CSV.

Roth EcoDWT plus 3

Roth publishes gallons, liters and percentage full together for five models. The official installation manual and the standalone chart disagree at one 1000L cell, so the table uses the manual's internally consistent value and leaves the conflict visible.

Table 9. Selected Roth EcoDWT plus 3 fill-chart rows

Source: Roth North America, EcoDWT plus 3 Installation Instructions and standalone Fill Chart, retrieved July 27, 2026. ● rows mark each model's published 95% row. † The installation manual prints 135 U.S. gallons at 30 inches; the standalone chart prints 125 while retaining 511 liters and 49%. ⚠ Both documents print 56 liters at 32 inches; 148 U.S. gallons converts to 560.3 liters. Roth states that filling above 95% is not permitted and that vent-whistle length may reduce maximum fill.

Why is no Granby horizontal steel chart published here?

Granby's U.S. Standard product page labels its capacity-chart link "Capacity Chart for US Horizontal Tanks," but the destination file is named and titled "Capacity Chart for Vertical Tanks." As verified July 27, 2026, that link therefore does not support a Granby horizontal gallons-per-inch table.

Highland Tank does publish separate horizontal tables. Its nominal 275-gallon chart reads 51 gallons at 10 inches in the vertical orientation and 97 gallons at 10 inches in the horizontal orientation, which shows why a vertical chart cannot be transferred to the rotated geometry. The Highland horizontal rows are not part of the released 396-row CSV and are not presented as Granby values.

How much do two manufacturers' charts for the same nominal vertical size disagree?

The released comparison aligns Granby and Highland Tank rows at each one-inch depth for nominal 230-, 275- and 330-gallon vertical tanks. The 275-gallon series stays within 1.6 gallons at every depth, while the 330-gallon series reaches 6.5 gallons; the reported means are mean absolute differences, not signed averages.

Table 10. Granby–Highland vertical-chart divergence

Source: Hartford Tank Removal Research calculation from Granby Industries, "Capacity Chart for Vertical Tanks," and Highland Tank, "Tank Gauge Charts" HT-6000-01/2021. All 132 matched rows are in the downloadable divergence CSV; calculated July 27, 2026.

Granby lists the compared 275- and 330-gallon vertical tanks at 44 inches high; Highland lists 44¼ inches. The dataset therefore measures differences between closely related nominal sizes, not one physically identical tank, and it does not assign the observed spread to undocumented manufacturing or rounding choices.

Table 11. Final published chart row compared with nominal label

Source: Granby Industries and Highland Tank manufacturer charts, retrieved July 27, 2026. "Difference from label" is chart value minus nominal label; the table does not treat the nominal label as a field measurement.

The comparison establishes that nominal labels and final chart rows are not interchangeable fields. It does not establish that either manufacturer's chart is wrong.

How much oil does a 275-gallon tank really hold?

The question mixes at least three quantities: nominal model capacity, liquid volume at a charted depth and an operational fill or usable amount. Granby and Highland publish 273.8 and 275 gallons at the final row of their compared vertical charts, while seven secondary sources publish about 225 to 251 gallons under definitions that are not consistent enough to combine.

Table 12. Published 275-gallon figures and what each source says it describes

Source: each publication named in the table; URLs are listed in the Sources section. The seven nonmanufacturer sources are presented as a terminology audit, not as primary technical authority and not as inputs to an average.

How was this collected and checked?

The release is a documentary dataset built from manufacturer and government sources checked July 27, 2026. It preserves source cells, publishes known conflicts and separates manufacturer measurements from calculations so every consequential number can be traced or reproduced.

Table 13. Reproducible obround-shell consistency check

Source: Hartford Tank Removal Research calculation from manufacturer dimensions and the 44-row vertical-chart series. Calculated July 27, 2026. The bare 27 × 44 × 60-inch Granby shell model, before the fitted multiplier, computes to 267.936 U.S. gallons at full depth.

The close Granby fit demonstrates that a simple obround-shell model is mathematically consistent with the published rows after one fitted multiplier. It does not disclose or prove Granby's internal engineering method.

This is a documentary dataset, not a field survey. The release reads manufacturer documents and official records; it does not measure installed tanks.

What did the source-integrity audit find?

The audit flags cross-document conflicts, internally inconsistent unit cells, label-versus-chart gaps and unavailable source links so they are visible rather than silently resolved. Publication treatment is stated for each finding.

Table 14. Source-integrity findings and publication treatment

Source: the Granby Industries, Roth North America and Highland Tank primary documents identified in each row; verified July 27, 2026. The same ten records, with source URLs, are in the downloadable source-integrity CSV.

Which tank-capacity thresholds change a standard or regulatory scope?

Capacity can change which technical standard or regulatory program applies, but similar-looking gallon thresholds govern different questions. The table separates manufacturer-listing scope, federal SPCC applicability, federal UST exclusions and Connecticut's residential/nonresidential rules instead of combining them into one ladder.

Table 15. Verified capacity thresholds and legal scope

Source: UL Standards & Engagement; 40 CFR 280.12; U.S. EPA SPCC guidance updated April 24, 2026; Connecticut DEEP residential guidance, five-or-more-unit guidance and May 6, 2026 UST regulations briefing. All checked July 27, 2026.

The federal heating-oil exclusion and the Connecticut program answer different questions. A tank excluded from the federal UST definition can still fall within a state program, and a Connecticut partial exemption below 2,100 gallons does not remove closure or failure requirements.

How do Connecticut rules change by tank type and capacity?

Connecticut draws the first residential line by the number of units served, not by a residential tank's gallon label. DEEP does not regulate the installation and use of a heating-oil UST serving four units or fewer under its UST program, while removal contractor, training, local-permit and leak rules still apply; a tank serving five or more units is nonresidential.

Source: Connecticut DEEP, "Residential Home Heating Oil Tanks," "Residential Home Heating Oil Tanks—FAQs," "Underground Storage Tanks Serving Five or More Residential Units," "Residential Underground Home Heating Oil Tank Releases" and the May 6, 2026 UST regulations briefing; Connecticut General Statutes Chapters 400 and 541. Checked July 27, 2026.

See also: Oil Tank Removal Requirements by State (2026) — the full 50-state reference dataset including Connecticut and Hartford details.

What do current Census and consumption data show about heating oil?

Heating oil remains far more prevalent in Connecticut than in the country as a whole, while Hartford city is below the statewide share. The table uses the Census Bureau's own 2024 one-year estimates and margins of error and labels EIA's winter-consumption figure as a forecast rather than a measurement of every household.

Table 16. Current heating-oil and housing context

Source: U.S. Census Bureau American Community Survey tables B25040 and B25035, 2024 one-year estimates, released September 11, 2025; U.S. Energy Information Administration, Winter Fuels Outlook for 2025–26. Percentages and Connecticut's rank were calculated from the official estimates; verified July 27, 2026.

The ACS category is "fuel oil, kerosene, etc." and its universe is occupied housing units. The estimates do not count tanks, identify tank sizes or show whether a property's tank is aboveground or underground. EIA's roughly 400-gallon figure is an average winter forecast for oil-heated households, not evidence that one tank size became standard for a particular reason.

Which heating-oil tank safety facts belong with a size chart?

The relevant safety facts explain why model identity, weight, pressure rating and leak status cannot be treated as chart trivia. They do not provide a procedure for moving, opening, entering, cutting, disconnecting, testing or removing a tank.

Source: Granby Industries U.S. Standard product specifications; Connecticut DEEP residential release guidance. Checked July 27, 2026.

What are the limitations of this heating oil tank size chart?

Which figures and source gaps were excluded from publication?

The audit closes unresolved gaps by excluding the unsupported figure rather than leaving a placeholder or supplying an estimate. These exclusions are part of the release record and explain why several commonly repeated numbers do not appear in the final tables.

What is included in the dataset download?

The release consists of four versioned CSV files that separate model dimensions, manufacturer chart cells, calculated chart differences and source-integrity findings. The files publish their source URLs and verification fields so the page's main claims can be checked without extracting them from prose.

What are the citation details for this page and dataset?

The details below identify the publication, page, dataset version and verification date. They are provided as neutral attribution metadata and do not request or condition any link, citation or reuse.

Manufacturer specifications and published chart values remain attributed to their publishers throughout. The cross-manufacturer data schema, 132-row divergence analysis, geometric consistency check and ten-record source audit are the work of Hartford Tank Removal Research.

What are the most frequently asked heating-oil tank chart questions?

These answers restate the page's primary lookup findings in forms that remain accurate when read by themselves. Each answer uses the same model, orientation and definition boundaries as the tables above.

Which primary sources support this page?

The manufacturer, regulator, statute and official statistical sources below support the technical and legal claims in the page. The final seven entries are secondary publications used only for the labeled 275-gallon terminology audit, not as substitutes for manufacturer specifications. All sources were retrieved or rechecked July 27, 2026 unless a document date is stated in its title.

1. Granby Industries. Standard Residential Oil Storage Tank UL-80 product page. granbyindustries.com
2. Granby Industries. Capacity Chart for Vertical Tanks. PDF
3. Granby Industries. Residential and Light Commercial Tanks brochure, revision 06/12/26. PDF
4. Granby Industries. Residential tank brochure, revision 05/20/25. PDF
5. Granby Industries. 2-in-1 Double-Wall Oil Tank product page. granbyindustries.com
6. Granby Industries. 2-in-1 720 L / 190-gallon capacity chart. PDF
7. Granby Industries. 2-in-1 1,000 L / 265-gallon capacity chart. PDF
8. Granby Industries. Fiberglass vertical single-wall oil-tank product page. granbyindustries.com
9. Granby Industries. Fiberglass 200-imperial-gallon capacity chart. PDF
10. Granby Industries. Fiberglass 250-imperial-gallon capacity chart. PDF
11. Roth North America. EcoDWT plus 3 Fill Chart. PDF
12. Roth North America. EcoDWT plus 3 Installation Instructions. PDF
13. Highland Tank. Tank Gauge Charts HT-6000-01/2021. PDF
14. UL Standards & Engagement. UL 80 published scope. shopulstandards.com
15. UL Standards & Engagement. UL 2258 published scope. shopulstandards.com
16. Electronic Code of Federal Regulations. 40 CFR 280.12—Definitions. ecfr.gov
17. U.S. Environmental Protection Agency. Who is regulated by the SPCC Rule?. epa.gov
18. Connecticut DEEP. Residential Home Heating Oil Tanks. portal.ct.gov
19. Connecticut DEEP. Residential Home Heating Oil Tanks—FAQs. portal.ct.gov
20. Connecticut DEEP. Underground Storage Tanks Serving Five or More Residential Units. portal.ct.gov
21. Connecticut DEEP. Residential Underground Home Heating Oil Tank Releases. portal.ct.gov
22. Connecticut DEEP. UST Clean-Up. portal.ct.gov
23. Connecticut DEEP. Underground Storage Tank Regulations Briefing, May 6, 2026. PDF
24. Connecticut General Assembly. Chapter 400, including current CGS §20-420. cga.ct.gov
25. Connecticut General Assembly. Chapter 541, recording repeal of former CGS §29-320. cga.ct.gov
26. U.S. Census Bureau. 2024 ACS 1-year table B25040, House Heating Fuel. data.census.gov
27. U.S. Census Bureau. 2024 ACS 1-year table B25035, Median Year Structure Built. data.census.gov
28. U.S. Census Bureau. 2024 ACS data-release record. census.gov
29. U.S. Energy Information Administration. Winter Fuels Outlook. eia.gov
30. InspectAPedia. Heating Oil Storage Tank Size. inspectapedia.com
31. OilTankCharts. Why a 275 gallon tank holds about 240. oiltankcharts.com
32. Bottini Fuel. How Much Oil Can My Heating Oil Tank Hold?. bottinifuel.com
33. C&K Smith Superior. Understanding Home Heating Oil Tank Sizes. cksmithsuperior.com
34. Hocon Gas. Heating Oil Basics: How to Read an Oil Tank Gauge. hocongas.com
35. Burt's Reliable. How Much Oil Does a 275 Gallon Tank Hold?. burts.com
36. HeatingHelp. True oil tank capacity practitioner discussion. forum.heatinghelp.com

The final seven sources are cited only as published secondary definitions and reported amounts in Table 12. They are not used to establish model dimensions, manufacturer chart cells, statutes, regulations or ACS estimates.