Oval Tank Volume calculator

Elliptical horizontal tank volume at any fill depth. Exact geometry, instant results, nothing leaves your browser.

FIG. 1 — TANK CROSS-SECTION · LIVE

SCALE AUTO · REV A

01 · Tank shape

02 · Dimensions

Dim. unit

Liquid

03 · Fill depth (dipstick)50%

Wetted depth—

Surface width—

Ullage—

Liquid volume at fill depth

—US gal

Total capacity—

Filled · liters—

Filled · ft³—

Percent full—

Liquid weight—

Remaining to full—

Exact segment geometry — see methodology. Dished-head propane math is documented there too.

True elliptical tanks appear in transport and marine applications where height clearance matters. This calculator treats the cross-section as a genuine ellipse and computes the partial-fill area by exact affine scaling of the circular segment — no lookup tables, no polynomial fits.

Heads-up: if your "oval" tank is a home heating oil tank with flat sides and rounded top and bottom, that is an obround, not an ellipse — use the heating oil calculator instead, which is several percent more accurate for that profile.

How this is calculated

Total volume

V = πab·L

Filled volume at liquid depth h

V(h) = (a/b)·[b²·acos((b−h)/b) − (b−h)·√(2bh−h²)] · L

An ellipse is a circle scaled horizontally; the segment area scales by the same factor, then × length. See the full derivation, a worked example and a fill-ratio table on the elliptical (oval) tank formula page.

FAQ

TVC-106/FAQ

Is my oil tank an oval or an obround?

Run your hand down the side: if there is a flat vertical band between the curved top and bottom, it is obround. Standard 275/330 tanks are obround.

Does orientation matter?

Yes — width is the horizontal axis and height is the vertical axis of the ellipse as installed; swap them if the tank is rotated.