There are spreadsheets on this website, intended either for interactive use, including Units Conversion and Budget Pricing of Tanks or as Demonstrations of others offered for sale.

Apparently, their online usability is not as widely available as I had hoped it might be, so they are now grouped together, with a few extras that may be useful and offered as an Excel workbook under the shareware principal. They are free and don't nag. If after using them, you find them useful, please consider sending $10 to help support with their development. You will then receive automatic updates.

The extras included at this stage are:

For calculating overall tank dimensions including coned or dome ends and the respective volumes. 

For determining the basic thicknesses of stainless steel pressure vessels, according to the code.

For calculating the internal and shipping volumes and the weight of hollow metal spheres.

For calculating accrued savings attracting variable compound interest and tax rates. 
  It can also be used to calculate loan repayment options.

For metric units click►Metric Units    and for US units►US Units 

You will receive a self extracting zipped Excel spreadsheet. Double click it and it will create a new directory called ~EOL at or near the top of your C: drive. If your explorer window was open, you may need to press F5 for it to show. Then just double click the .xls file.