An Excel alternative for engineering calculations

The same calculation, written out

In a spreadsheet, a bending stress is a number in a cell whose formula reads something like =B4/B5, with the unit conversion done by hand. In a sheet it is:

# Bending stress

M: 54 kN*m | design moment
Z: 691.76 cm^3 | section modulus
sigma: M / Z -> MPa | bending stress

The report shows the formula, the numbers substituted and the result: 78.06 MPa. The engine converted kN·m divided by cm³ into MPa because you asked for MPa. A reviewer reads the page top to bottom and does not need to open anything.

Where a calculation sheet is stronger

• Units are part of the value. A spreadsheet stores a bare number, so a kN in one cell and a N in another add without complaint. Here the engine tracks units, converts them, and refuses to add a length to a time.
• Formulas are readable. Names such as M and Z instead of B4, and the typeset formula appears in the output.
• The workings are the output. Each result shows its formula and its substituted numbers, ready to print.
• Inputs are explicit. A template marks its inputs with a question mark and presents them as a form. The cells you may change are not mixed with the cells you must not.
• Branching reads like text. An if line prints a plain sentence such as "OK" or "choose a deeper section".

Where a spreadsheet is still better

Use a spreadsheet for tables of many similar rows, quick what-if columns, data you will sort or filter, pivot tables, and anything shared with people who only have Excel. A calculation sheet is for a calculation with a story: inputs, steps and checks that you want to read and file. Many engineers use both.

Getting the results into Excel

Export gives you a workbook with the report in document order. Each equation is a row with its description, name, expression, the expression with numbers put in, value and unit. There are separate sheets for variables, for each vector or matrix, for the inputs and for plot data, and plots become native Excel charts that you can edit.

Be clear about what you get: the cells hold calculated values with the expressions as text. They are not live Excel formulas, so changing a cell in the workbook does not recalculate the rest. The workbook opens in LibreOffice and a Python reader. We have not tried it in Microsoft Excel, so check it opens as you expect.

If you want a document rather than a workbook, export Word, with real equations, or print the report to PDF.

Moving a spreadsheet calculation over

Take the cell that holds the answer, and work backwards. Write each input as a line with its unit, then each formula as a line using those names. Keep the same numbers and check the result against the spreadsheet. A good first target is a calculation you repeat often, because you can turn its inputs into a template and reuse it as a form.