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Tank volume from level

Enter dimensions, head type and measured level to get volume, fill, mass and a calculated strapping table for horizontal or vertical tanks.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

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Measurement

Diesel is about 52 lb/ft³ (840 kg/m³), fuel oil 59 to 62, water 62.3 at 68 °F.

—Volume at the level entered
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Level versus volume curve

Cumulative volume versus level; the dot marks the current reading.

Tap the chart to see the values.

Calculated strapping table

The report gathers this page's inputs, results, equations, assumptions and references, with fields for project, engineer and revision. In the print dialog, choose Save as PDF.

Method, assumptions and references

Equations used

Circular segment (horizontal tank): A(h) = R² arccos((R − h) ÷ R) − (R − h) √(2Rh − h²); V = A(h) × L
Two elliptical, hemispherical or F&D heads (horizontal): V = (a ÷ R) × π h² (3R − h) ÷ 3
Elliptical bottom (vertical): V = π R² (h² ÷ a − h³ ÷ (3a²)); conical bottom: V = π R² h³ ÷ (3a²)
Head depth: 2:1 elliptical a = D ÷ 4; hemispherical a = D ÷ 2; ASME F&D with equivalent depth a = 0.1545·D (volume 0.0809·D³)

Assumptions and limits

  • Inside dimensions and a level tank; tilt, deformation and internals not considered.
  • The F&D head is modeled as an ellipsoid of equal volume: total volume is exact, the level distribution is approximate.
  • Constant density; correct for temperature in custody measurement (ASTM D1250 / API MPMS Ch. 11.1).

Standards and technical documents

  • API MPMS Chapter 2.2E / ISO 12917-1:2017: Calibration of horizontal cylindrical tanks — Manual methods
  • API MPMS Chapter 2.2A / ISO 7507-1: Calibration of upright cylindrical tanks
  • ASME BPVC Section VIII, Division 1: head geometries (2:1 ellipsoidal, hemispherical, torispherical)
  • API MPMS Chapter 11.1 / ASTM D1250: temperature and pressure volume correction factors

U.S. regulations

  • OSHA 29 CFR 1910.106: flammable liquids storage (tank design, venting and diking)
  • EPA 40 CFR Part 112 (SPCC): secondary containment for oil storage tanks
  • NFPA 30: Flammable and Combustible Liquids Code (adopted by state and local fire codes)

Frequently asked questions

How do I get horizontal tank volume from level?

Shell volume is the area of the circular segment below the level times the length. Each head adds a volume that depends on its depth. The calculator adds both and builds the level-versus-volume table.

Can I use the calculated table for custody transfer?

No. For custody, sales or fiscal measurement, the official strapping is done by physical tank calibration per API MPMS and ISO 12917. Use this table for operations and estimates.

What is the volume of a 2:1 elliptical head?

Each 2:1 elliptical head holds π·D³ ÷ 24, about 0.1309·D³. For an 8 ft diameter tank, that is about 67 ft³ (500 gal) per head.