This is probably the best Tank Volume Calculator available over the internet, and
there are lots of them. If you know of a better one, please let us know by using the
Contact form. It is currently not for sale, but if you have an interest in it,
let us know and we can accelerate its completion. This program can determine the volume of any tank
described in the original "Buffalo Handbook" within ± 0.2%. Scroll down to see all the features
of this handy executable program.
Ref: "Buffalo Handbook  Design Data and General Information on Welded Tank and Plate
Fabrication", Buffalo Tank Corporation, 6th Printing, (1951): Note: Those were the days that you
could actually get tables of data! I'd like to thank Bill Hutchings for allowing us to use his book.
Its not easy finding this kind of information these days.
The window to the rightgives the total volume for the given tank. Some of the drop down menus are
shown below. They show the choices that are given for each parameter.

Click on the image for a better view. 
A subsequent window allows you to state the liquid level or liquid volume
in the tank. The level can be chosen from the tank bottom, a distance from a
reference point in the tank, a distance below a structure above the tank, as a
percent of the total height, as the absolute volume, or as a percent of the total volume. Similar to
TKSolver, you can input any of these and the others are all calculated.
Key Benefits
The main benefit of this program over others is its versatility and
choices of standard tank configuration. This program is not just restricted to standard flat,
ASME or elliptical tanks. When you see the choices in the Buffalo Handbook, you have to come
to the conclusion that no tank is a standard.

Four different basic tank shapes can be chosen. 

The program calculates both vertical and horizontal tank orientations. 

Both bottom and top head shapes can be independently chosen. If you chose Other,
Conical, or Angular
another submenu will popup asking for specifics, such as depths and angles. If you pick Other, you have
the choice of picking various dished bottom tank standards, such as Standard and Shallow Flanged and
Dished Head Types and the German Klöpperboden heads or you can choose the dish and knuckle radii. 

There is a large selection of length dimensions to choose from. If your favorite
dimension is not given,
let us know so we can include it in a future update. 

There are more units to choose from in determining the default volume units.
Not shown in this picture are:
mL, cubic ft, Barrels Oil and cubic yards. 

The angular units can be either degrees or radians. 

Once the above defaults are chosen, they are inserted in the central area of the window.
But of course, even the defaults can be changed! Each drop down menu gives you the above choices
again. When you change a unit, it automatically converts the previous value to a new value
corresponding to the new unit. 
 Dimensionless numbers are also shown to the far right of the window. 
