Get AI to write any Excel formula for you

Every formula you need, without learning them

The trick isn't knowing formulas. It's describing your spreadsheet clearly, and this guide teaches exactly that.

• Get a working formula for almost anything: totals with conditions, lookups between sheets, dates, text clean-up, ranking, "if this then that"
• Understand any formula someone else left in a spreadsheet
• Fix #N/A, #VALUE!, #REF! and other errors in seconds
• Build formulas that copy down a whole column correctly
• Keep your company's data out of the AI entirely, because you only describe your columns and never upload the data

Good for: anyone whose job involves spreadsheets but never had Excel training, people who inherited a mysterious spreadsheet, and managers who need numbers without waiting for the data team.

What you need

Do it in seven steps

1. Learn the one habit that makes it work

   The AI can't see your spreadsheet. If you ask "how do I total the sales?" it has to guess which columns you mean, so it guesses wrong. Give it three things every time:

   1. Your columns: the letter and the header of each one that matters.
   2. Where the data is: for example "headers in row 1, data in rows 2 to 301".
   3. What you want and where: "In column I, I want..." or "In cell L2, I want...".

   Here's a reusable starter. Fill it in once, save it in a note, and paste it at the start of every formula question:

   Copy this promptCopy

   I'm using Excel [version, e.g. Microsoft 365 / Excel 2019 / Google Sheets]. I'm not a formula expert, so please explain simply.
   
   My sheet is called "[Sheet name]". Headers are in row 1 and the data is in rows 2 to [last row].
   The columns are:
   A: [header] (e.g. Order ID, text like ORD-1001)
   B: [header] (e.g. Order Date, a date)
   C: [header] ...
   [add the rest]
   
   What I want: [describe it in plain English]
   Where I want it: [cell or column]
   
   Please give me the exact formula to paste in, tell me which cell to put it in, and whether I should copy it down.

   Tip: if you're not sure how to describe a column, copy the header row and 3 or 4 rows of data and paste them in. If the data is real customer or staff information, change the names and numbers first. The AI only needs to see what the data looks like.

2. Your first formula, a total with conditions

   Using the practice spreadsheet, ask for the total sales for one region in one month. That's the kind of question that normally sends people to Google.

   Copy this promptCopy

   I'm using Excel (Microsoft 365). My sheet is called "Sales". Headers are in row 1, data in rows 2 to 301.
   A: Order ID
   B: Order Date (a real date)
   C: Customer
   D: Region (North, South, East or West)
   E: Product
   F: Quantity (number)
   G: Unit Price (number)
   H: Sales Rep
   
   First, in column I, I want "Total" = Quantity × Unit Price for each row.
   Then in cell L2, I want the total of column I for the North region in March 2026 only.
   
   Please give me both formulas, tell me where to put each one, and explain the second one in simple words.

   The AI will probably give you =F2*G2 for column I and a SUMIFS formula for L2. Paste them in. To fill column I quickly, double-click the small square at the bottom-right corner of cell I2 and Excel copies the formula all the way down.

   Check it. Filter the Region column to North and look at the March rows. Does the total roughly match? It's a good habit for every new formula.

3. Make it reusable

   Typing "North" and "March" into a formula means editing it every time. Ask the AI to make it flexible:

   Copy this promptCopy

   That works. Now I want to type a region in cell K2 and a month in cell K3 (like 01/03/2026), and have L2 update automatically. Please rewrite the formula to use those cells, and suggest a dropdown for K2 so people can only pick North, South, East or West.

   The AI will explain how to add a dropdown with Data Validation. You've just built a mini report that anyone in your team can use.

4. Look things up from another sheet

   The most-searched Excel problem of all: pulling a value from another table. Say you have a second sheet called "Reps" with each sales rep's team and manager.

   Copy this promptCopy

   I have two sheets in Excel (Microsoft 365).
   Sheet "Sales": column H is Sales Rep (a full name), data in rows 2 to 301.
   Sheet "Reps": column A is Rep Name, column B is Team, column C is Manager. Data in rows 2 to 9.
   
   In Sales column J, I want each order's Manager, looked up from the Reps sheet using the rep's name. If the name isn't found, show "Not found" instead of an error.
   
   Please give me the formula for J2 and tell me if I should copy it down. If XLOOKUP isn't available in older Excel, give me the VLOOKUP version too.

   Tip: always ask the AI to handle "not found". It saves you from a column full of #N/A.

5. Fix a formula that's broken

   When a formula gives an error or the wrong number, don't start again. Paste it in with what you see:

   Copy this promptCopy

   This Excel formula is in cell J2 and shows #N/A for most rows, even though I can see the names in the other sheet:
   
   [paste the formula here]
   
   Column H in "Sales" has names like "Grant, Quinn" but the Reps sheet has "Quinn Grant". What's wrong and how do I fix it? Please give me the corrected formula.

   The AI is very good at spotting the usual causes: extra spaces, names written differently, numbers stored as text, or a range that doesn't go down far enough.

6. Understand a formula someone else wrote

   Inherited a spreadsheet full of mysterious formulas? Click the cell, copy what's in the formula bar, and ask:

   Copy this promptCopy

   Please explain this Excel formula in plain English, step by step, as if I've never seen these functions before. Then tell me if there's a simpler way to write it.
   
   [paste the formula here]

7. Save your best prompts

   Keep a note called "Excel prompts". Each time a formula works, save the prompt you used. In a month you'll have your own library for your own spreadsheets. Most people only ever need five or six.

Quick fixes

Use it on your own work

The same describe-your-columns habit works for almost any spreadsheet task:

One skill instead of fifty functions

Formula courses teach you 50 functions you'll forget. This teaches you one skill: describing your problem clearly to an AI. It works for every formula you'll ever need, in any spreadsheet, and it keeps your company's data on your computer, because the AI only ever sees your column names.

What to build next