Engineering calculations with AI: compute, check and document properly
AI can save hours on structural, hydraulic or electrical calculations, and on checking a calculation note someone sent you. But only if it shows formulas, units, assumptions and clause numbers, and you check every number. Here is the free route, the paid route, and how to work without getting burned.
01AI is a brilliant junior engineer, not the engineer of record
Think of AI as an engineer who graduated yesterday: very fast, knows lots of formulas, writes a neat calculation sheet. But sometimes it sounds sure of itself while using the wrong unit or quoting the wrong clause. So you never sign what it wrote before you check it, just like with an intern. The responsibility stays with you.
02Free route vs paid route
Free: AI chat plus open calculation tools
- Claude's free plan runs Python and returns a calculation with units
- Free ChatGPT gives limited data analysis
- Wolfram|Alpha on the web checks a formula or unit conversion in seconds
- SMath Studio (free for personal use) for a calculation sheet with units
- Jupyter plus Python plus handcalcs for a sheet that looks hand-written
Limit: Daily usage limits; large files and long chats hit the cap quickly
Paid: more usage and Excel integration
About 20 USD a month for Claude Pro or ChatGPT Plus (checked on vendor pages)
- Claude Pro: much more usage, Projects with your standards and templates, and Claude for Excel
- ChatGPT Plus: Python data analysis without the free-plan limits
- Microsoft 365 Personal (about 10 USD a month) includes Copilot in Excel
- Wolfram|Alpha Pro: step-by-step solutions and file uploads
When paying is worth it: When you calculate or review calculations every week, or live in Excel
03The right way to work
- 1DefineInputs, units, code and National Annex
- 2AI computes in codeAsk for Python or a sheet, not a guess in prose
- 3Demand transparencyFormula, units, assumptions and clause per step
- 4CheckOrder of magnitude, hand check, the standard itself
- 5Final designIn approved software, signed by an engineer
04The best tools for engineering calculations
Claude
AnthropicBest at: Writes and runs Python, builds a clean calculation sheet and reviews an existing calc note in PDF.
Chat with code execution and file creation, up to 5 Projects
Pro about 20 USD a month (17 billed yearly): more usage and Claude for Excel
Add-ons that help 5
- SettingCode execution and file creationSettings, then Capabilities: Claude runs the math in code instead of guessing.included
- ModeExtended thinkingLonger reasoning for multi-step problems.included
- Add-onClaude for ExcelWorks inside the workbook, explains formulas with cell citations and traces errors.paid
- SettingProjectsKeep your office templates and instructions available in every chat.included
- ConnectorWolfram MCP (Cloud)Plugs in Wolfram's computation engine; a free service for light use.free
ChatGPT
OpenAIBest at: Analyses data files and computes in Python; good for measurement tables and charts.
Limited data analysis and file uploads
Plus at 20 USD a month: full data analysis and more usage
Add-ons that help 3
- ModeData analysis (Python)Runs Python in a notebook environment and shows the code.included
- GPT/GemWolfram GPTAdds a real math engine and curated data. Search Wolfram in the GPT store.free
- SettingProjectsKeeps one job's files and instructions together.included
Wolfram|Alpha
WolframBest at: A true computation engine: integrals, equations, unit conversions and formula checks.
Web calculations with no sign-up
Pro: step-by-step solutions, file uploads and longer compute time (check current price)
Add-ons that help 2
- ConnectorWolfram MCPConnects Wolfram to Claude, ChatGPT and Cursor; the Cloud version is free for light use.free
- Add-onWolfram|Alpha ProShows the solution steps; great for learning and checking.paid
Microsoft Copilot in Excel
MicrosoftBest at: When the calculation already lives in the office Excel sheet: formulas, checks and charts.
No Copilot in Excel without a subscription
Included in Microsoft 365 Personal (about 10 USD a month) and Family, with usage limits
Add-ons that help 2
- SettingMicrosoft 365 Personal / FamilyThe subscription that turns on Copilot in Excel, Word and PowerPoint.paid
- Add-onMicrosoft 365 PremiumHigher usage and AI agents for longer tasks, about 20 USD a month.paid
Gemini
GoogleBest at: Explains formulas and standards; works well with Google Docs and Drive.
Free Gemini with Canvas and Gems
Google AI Pro about 20 USD a month: stronger model and Gemini inside Google apps
Add-ons that help 2
- GPT/GemYour own GemSet fixed rules: SI units, always cite the clause.free
- ModeCanvasEdit a calculation sheet or code next to the chat.free
SMath Studio + Jupyter + handcalcs
Free and open sourceBest at: A transparent calc sheet with units you can check and file. AI writes it, the tool computes it.
SMath is free for personal use; Jupyter, Python and handcalcs are fully free
SMath for organisations needs a paid licence
Add-ons that help 3
- Add-onhandcalcsTurns Python code into a hand-calc style sheet with numbers substituted.free
- Add-onforallpeople / PintPython unit libraries that catch kN vs N mistakes.free
- Add-onJupyterLabA notebook to run, document and export to PDF.free
05Example: steel beam deflection
06Example: pressure loss in a water pipe
07Example: anchor edge distance check
08Which tool for which calculation
| Task | Recommended tool | Why |
|---|---|---|
| Quick structural check (beam, column, deflection) | Claude or ChatGPT with code execution | Computes in code, shows formula and units |
| Reviewing a calc note you received as PDF | Claude with Projects | Reads long documents and returns a findings table |
| Solving an equation, integral or unit conversion | Wolfram|Alpha | Deterministic engine, not a guess |
| An existing office Excel workbook | Claude for Excel or Copilot in Excel | Works in the cells and explains every formula |
| A calc sheet to file with the project | SMath Studio or Jupyter plus handcalcs | Transparent, with units, every line checkable |
| Electrical (voltage drop, cable size) | Claude or ChatGPT, then check the standard | Fast, but factors from the Israeli standard must be verified |
| Pipe pressure loss and flow | Python in Jupyter, or AI with code execution | Colebrook needs iteration; code does it right |
| Final design for signing | Approved professional software | AI does not replace recognised design tools and engineering review |
09Get started in 5 minutes
- 1
Turn on code execution
In Claude: Settings, Capabilities, enable Code execution and file creation. In ChatGPT, explicitly ask it to compute in Python.
- 2
Open a Project
Upload your office template, section tables and relevant ETA pages, and add standing instructions.
- 3
Write standing instructions
For example: use SI units, write the formula before substituting, cite code and clause, list every assumption.
- 4
Give complete inputs
Geometry, materials, loads, code and National Annex. Whatever you leave out, the AI will guess.
- 5
Check twice
Order of magnitude in your head, then a cross-check in another tool such as Wolfram|Alpha or SMath Studio.
- 6
Compare with the original standard
Open the clause in the official document and confirm the formula and factors are really there.
10Do and don't
Do
- Ask for the calculation in code, not free text
- Demand units on every line
- Ask for the clause number and look it up
- Use AI as a second reviewer of a calc note
- Keep the code and output for your records
Don't
- Trust a value the AI remembers from a standard
- Upload sensitive client documents without approval
- Submit an AI calculation without engineering review
- Replace approved design software
- Forget that responsibility stays with the engineer
11FAQ
Can I submit a calculation made by AI?
You can use it as help, but an engineer must check every formula, unit and assumption. For final design, use recognised professional software. The professional responsibility is yours.
Does AI know the Eurocodes?
It knows many formulas, but it can mix up editions, clauses and National Annexes. Always check against the official document, and ideally upload the relevant extract to a Project.
Why ask for code instead of a plain answer?
A language model doing arithmetic in its head can slip. Code that actually runs computes exactly what it says, and you can read and check it.
What is the best free setup?
A combination: free Claude or ChatGPT to write the calculation, SMath Studio or Jupyter with handcalcs for a transparent sheet, and Wolfram|Alpha for a cross-check.
What about privacy?
Do not upload sensitive client documents without permission. Check your plan's privacy settings; in an office, a business plan with data controls is better.