How to use these prompts
Distinguishing two uses changes everything. For calculations, the AI must give you the tool (the formula, the steps for the pivot table) that you then run in the spreadsheet: this way the math is done by the software, not the model's memory. For reading, you can paste the table and ask what it means: there the AI reads, it doesn't calculate, and it makes far fewer mistakes.
One caution that's non-negotiable: if you upload a file with customer data, revenue or personal information, you're sending sensitive data to an external service. For truly confidential numbers, anonymize (remove names and identifiers) or work only on the structure, not the real data. And always verify the totals of a new formula on two test rows before trusting it.
The prompt library
The formula that won't come to you
Give me the Excel formula (and the Google Sheets version if different)
to get this result. Explain in one line what it does and which cells
to apply it to. If there are different ways, give me the simplest to
understand, not the most elegant.
What I need to calculate and how the table is organized (which data in
which columns):
Understand a table at a glance
I'm pasting you a table of data. Tell me in five points what it says:
the highest and lowest values, the obvious trends, anything strange or
out of scale that deserves a check. Don't calculate complex sums
yourself: instead point me to the formula to verify them in the sheet.
Table:
Which chart to use for this data
I have this data and need to show it to someone. Tell me which type of
chart makes it clearest (and which to avoid and why), what to put on the
axes, and how to title it so it's understood without explanations. Think
about the viewer, not about showing off.
What the data contains and who I need to show it to:
Clean up messy data
This data is dirty: different formats, duplicates, empty cells, text
where numbers should be. Tell me step by step how to clean it in Excel
or Sheets (with the formulas or functions to use), starting from the
worst problem. Don't rewrite the data yourself: give me the method to
clean it.
Description of the mess (or a chunk of the data):
Build a pivot table
I want to summarize this data with a pivot table but don't know how to
set it up. Tell me what to put in rows, columns and values to answer
this question, and the steps to create it. If I prefer an equivalent
formula (like SUMIFS), give me that too.
The data I have and the question it needs to answer:
A concrete example
Marco runs a shop and has a spreadsheet with six months of sales: date, product, amount, six columns, eight hundred rows. He wants to know how much he took in by category, but doesn't know how to use pivot tables and is afraid of making mistakes.
He uses the pivot prompt, describing the columns and the question ("total revenue by product category"). The AI tells him what to drag where and also gives him the alternative formula with SUMIFS for those who prefer formulas. Marco first tries the formula on a category he knows by heart: the total checks out. At that point he trusts it and extends it. In ten minutes he has the picture he'd been putting off for weeks. The AI never touched his numbers: it gave him the tool, the calculation was done by Excel.
When it does NOT work (and how to fix it)
If the numbers it gives you are wrong
When you ask the AI to calculate directly ("what's the sum of this column?"), it can get it wrong: it's not a calculator. The fix is structural: don't ask it for the result, ask it for the formula to paste into the sheet. The math is done by the software, the AI just writes the instructions.
If the formula doesn't work in your sheet
Sometimes the formula gives an error because your version uses the semicolon instead of the comma, or translated function names. Paste the AI the exact error message and say which language/version you use ("Italian Excel"): it adapts the syntax to your sheet. Most errors are about punctuation, not logic.
If you don't want to upload confidential data
If the data contains customer information or sensitive figures, don't upload the file. Describe only the structure ("column A dates, column B amounts") and ask for the formula on that: the formula works the same, and your data stays on your computer. The AI doesn't need to see the real numbers to tell you how to sum them.
A tip from someone who actually uses it
Always verify a new formula on two rows whose result you already know, before applying it to eight hundred. A logic error spreads silently across the whole sheet, and you notice it when the total is absurd or, worse, when it's only slightly wrong. The spot check costs thirty seconds and saves you from decisions made on false numbers.
Frequently asked questions
Can the AI directly modify my Excel file?
On its own, normally no: it gives you formulas and instructions that you apply. There are tools and add-ins that connect it inside the sheet and act on the cells, but they change often and aren't in every plan. To be safe, assume the AI advises and you execute: this way control over the data stays yours.
Can I trust the conclusions the AI draws from my data?
The reading observations yes, the judgments no without verification. If it says "sales drop in July", check that it's true by looking at the numbers. The AI sees patterns, but doesn't know the context: that drop might have been the summer closure, not a problem. The AI reads the data, you give it the meaning.
Do I need to know how to program or use complicated formulas to analyze data?
No, and that's the point. The whole sense of these prompts is precisely to ask the AI for the formula in your place: describe in words what you want to get and it gives you the tool already written. You need to know how to paste the formula in the right cell and verify that the result checks out, not how to invent it. The skill needed is control, not syntax.