Tank dimensions

Tank orientation

Width and height are the two axes of the elliptical cross-section. For a horizontal tank the dip is measured up the shorter axis.

Tank diagram

Cross-section view (horizontal tank). Switch orientation to see the vertical view.

Horizontal elliptical tank Three-quarter view of an elliptical tank with width, height, depth and length dimension lines. Height Width Depth Length

Calculated volume

Enter the tank dimensions and dip, then press Calculate Volume.

Dip Volume (gal) Volume (L) % Full

About this calculator

How elliptical tank volume is calculated

A horizontal elliptical tank is a trough whose cross-section is an ellipse. A dip h deep fills a partial segment of that ellipse, stretched along the tank length.

V = L · [ a·b·asin(h/a) + h·√(a² − h²) ]

where a is half the tank height, b is half the tank width, h is the dip measured above the tank bottom and L is the tank length. Cubic inches become US gallons by dividing by 231.

Measurement guide

How to dip a tank

Dip the stick from the fill opening down to the bottom and read the wet line. Measure the two cross-section axes at the widest and highest points, and the length inside end to inside end.

Assumptions

The tank is level, the ends are flat, and the cross-section is a true ellipse. A vertical tank stands on the ellipse, so the dip is measured along its length.