Tank dimensions

Tank diagram

Horizontal cylindrical tank Three-quarter view of a cylindrical tank with diameter, length and depth dimension lines. Diameter Length Depth

Calculated volume

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

Dip Volume (gal) Volume (L) % Full

About this calculator

How cylindrical tank volume is calculated

A horizontal cylindrical tank holds a partial circular segment of the cross-section, stretched along the tank. A vertical tank holds a flat circle that grows with the dip.

V = L · [(h − r)·√(2rh − h²) + r²·arccos((r − h)/r)]

where r is the tank radius, h is the liquid depth (dip) and L is the tank length. The result is converted from cubic inches to US gallons by dividing by 231.

Measurement guide

How to dip a tank

Lower a straight dipstick from the fill opening until it touches the bottom. Mark the wet line, pull the stick out, and read the depth from the bottom. For the diameter, measure across the widest inside of the tank. For a horizontal tank, the length is inside end wall to inside end wall.

Assumptions

The tank is level, the heads are flat-ended for horizontal tanks, and the dipstick is perpendicular to the surface. Rounded or dished ends, sloping tanks and baffle plates are not modelled here.