250 gallon tank: dimensions that work
250 gal = 946 L = 33.4 ft³. Full weight ≈ 2,086 lb of water. Below: every diameter/length pair that holds exactly this — geometry, not brand specs, so you can sanity-check any manufacturer sheet.
| Diameter | Length |
|---|---|
| 24 in dia | 128 in (10.6 ft) |
| 30 in dia | 82 in (6.8 ft) |
| 36 in dia | 57 in (4.7 ft) |
| 38 in dia | 51 in (4.2 ft) |
| Diameter | Height |
|---|---|
| 24 in dia | 128 in tall |
| 30 in dia | 82 in tall |
| 36 in dia | 57 in tall |
| 38 in dia | 51 in tall |
| 42 in dia | 42 in tall |
What 250 gallons is, in every unit that matters
250 US gal = 57,750 in³ (× 231, exact)
250 US gal = 33.4 ft³ (× 77/576)
250 US gal = 946 L (× 3.785411784, exact)
250 US gal = 0.946 m³ (× 0.003785411784, exact)Every factor above is exact by definition — see the conversion library for the derivations.Choosing proportions
The tables above give you the pairs of dimensions that hold this volume. Choosing between them is a trade between three things:
- Gauging resolution. A short, fat tank has more gallons per inch, so every reading error costs more. A tall, thin tank resolves finely but is harder to stick and easier to tip.
- Footprint and head height. Doubling the diameter quarters the length needed for the same volume, so small diameter changes move the length a lot. Check the delivery route, not just the final position.
- Structural load. The weight below is the contents alone, concentrated over whatever footprint you pick. Halving the footprint doubles the pressure on the slab or the framing underneath it.
For horizontal cylinders there is a fourth: the volume-per-inch curve is steepest at mid-height and shallowest at both ends, so a horizontal tank gauges well in the middle of its range and badly at the top and bottom. If your operating band is the last 20 %, a vertical tank of the same capacity will serve you better.
| Contents | Density | Weight of contents | Metric |
|---|---|---|---|
| Water | 8.35 lb/gal | 2,086 lb | 946 kg |
| No. 2 heating oil | 7.20 lb/gal | 1,800 lb | 816 kg |
| Diesel | 7.05 lb/gal | 1,762 lb | 799 kg |
| Gasoline | 6.30 lb/gal | 1,575 lb | 714 kg |
| Kerosene | 6.82 lb/gal | 1,705 lb | 773 kg |
Densities are the reference values tabulated on our methodology page, near 60–70 °F. Real fluids vary with temperature, grade and composition — a 10 °F swing moves a hydrocarbon density by roughly 0.4 %. Add the empty vessel weight to get a gross figure.
Have a tank with these dimensions already? Generate its inch-by-inch dip chart, or run partial fills on the universal calculator. Manufactured tanks add heads, legs and fittings — treat these tables as the geometric core and trust the nameplate where one exists.
The standards behind a capacity figure
The gallon itself is exact: 231 cubic inches, by definition in NIST Handbook 44, Appendix C. Everything downstream of that is geometry, and the geometry on this page is exact for the dimensions stated.
What is not exact is any real tank. For a capacity table that will hold up in a dispute or an audit, the tank must be calibrated by physical measurement under ISO 7507-1 (manual strapping) or the equivalent API MPMS chapters, with corrections for plate thickness, shell expansion and tank tilt. Computed geometry is the right tool for design, sizing and sanity-checking a supplier's sheet; it is not a calibration.
FAQ
What are the dimensions of a 250 gallon tank: that work?
See the table above — it lists the dimensions this page's capacity figures are computed from. Treat them as the standard trade geometry; an individual manufacturer's tank can differ, and where it does, the nameplate governs.
How much does a full 250 gallon tank: that work weigh?
About 2,086 lb of water, or less for a hydrocarbon — the weight table above gives the figure for each liquid. Add the empty vessel weight for a gross figure.
Is the rated capacity the same as the real capacity?
Rarely exactly. The rating is a trade label; the geometric figure above is what the stated dimensions actually hold. Both are useful — just be clear which one you are quoting when the number leaves your desk.
Sources and standards
The geometry on this page is computed, not copied. These are the documents that define the units it is expressed in and the codes that govern a tank in service.
- Handbook 44, Appendix C — General Tables of Units of MeasurementNational Institute of Standards and Technology, U.S. Department of Commercehttps://www.nist.gov/document/2026-nist-handbook-44-appendix-cThe legal-metrology reference for U.S. customary units. Fixes the U.S. liquid gallon at exactly 231 cubic inches and tabulates the full liquid-volume chain (minim → fluid dram → fluid ounce → gill → pint → quart → gallon).
- Special Publication 811, Appendix B.8 — Factors for Units Listed AlphabeticallyNational Institute of Standards and Technologyhttps://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8NIST's master table of conversions into SI. Factors printed in boldface are exact by definition rather than measured or rounded — which is how you tell a defined unit from an approximated one.
- ISO 7507-1 — Petroleum and liquid petroleum products: Calibration of vertical cylindrical tanks, Part 1: Manual strapping methodInternational Organization for StandardizationPaid standard — cited by designation; obtain from the publisher.Defines how a tank's capacity table (its “strapping table”) is produced from physical measurement, including corrections for plate thickness, shell expansion and tank tilt. It is the reason a real tank's chart rarely matches naive geometry to the last gallon.
- Manual of Petroleum Measurement Standards (MPMS) — Ch. 1 “Vocabulary”, Ch. 11.1 “Temperature and Pressure Correction Factors”, Ch. 12.1 “Calculation of Static Petroleum Quantities”American Petroleum Institute (with ASTM D1250 / ISO 91 volume correction tables)Paid standard — cited by designation; obtain from the publisher.The industry standard for turning a gauged tank volume into a traded quantity: observed volume, gross standard volume at 60 °F, and net standard volume after sediment and water. A unit conversion is only the first step of that chain.
- Methodology — the partial-fill formulas and liquid densities used on this sitetankvolumecalc.comhttps://tankvolumecalc.com/methodology/Every chart value here comes from a closed-form partial-fill formula, not interpolation: circular segments for cylinders, a piecewise obround model for 275/330 heating-oil tanks, and scaled spherical caps for dished heads. Densities and their bases are tabulated there.
Every linked source above was retrieved and checked on 2026-09-02. Factors quoted as exact are exact by definition in the cited document, not rounded by us.