Copilot in Excel (and ChatGPT for Formulas): A Plain-English Guide
Most people use about 5% of Excel and are slightly afraid of the other 95%. AI helps in two ways. Copilot in Excel works inside your spreadsheet if your Microsoft 365 plan includes it. ChatGPT, free, will write and explain the formula you could never remember. Both need you to check the answer, because a wrong total looks exactly as confident as a right one.
Quick answers
- Copilot in Excel can summarize data, suggest formulas, highlight and sort, and build charts. It needs a Microsoft 365 plan that includes Copilot, and works best on data formatted as a table in a file saved to OneDrive or SharePoint.
- ChatGPT for formulas: describe your columns and what you want, and ask for the formula plus a plain-English explanation.
- Always test a formula on a few rows you can check by hand before trusting it on 5,000.
- Do not paste confidential spreadsheets into a public AI tool. Describe the columns instead of uploading the data.
How do you get ChatGPT to write an Excel formula?
Describe the columns, not the data. ChatGPT does not need your customer list to write the formula, only the layout.
Typical answer: =SUMIFS(D2:D500, B2:B500, "West", A2:A500, ">="&DATE(2026,3,1), A2:A500, "<"&DATE(2026,4,1))
Check by hand: filter Region to West and Date to March, select the Amount cells, and read the Sum in the status bar at the bottom of Excel. The numbers should match.
That "check by hand" request is the most useful line in the prompt. It turns a formula you have to trust into one you can verify in thirty seconds.
What other formulas is ChatGPT good at?
- Lookups: "Find the price for each product code in column A from the Prices sheet" usually returns an XLOOKUP such as
=XLOOKUP(A2, Prices!A:A, Prices!B:B, "Not found"). - Cleaning text: splitting full names, trimming spaces, fixing capitals.
- Explaining a formula someone else wrote: paste it and ask "explain this like I'm new to Excel".
- Fixing errors: paste the formula and the error (#N/A, #VALUE!) and ask why.
Tell ChatGPT your Excel version. XLOOKUP needs Excel for Microsoft 365 or Excel 2021 or later; older versions need VLOOKUP or INDEX/MATCH instead.
How do you use Copilot in Excel?
- Click inside your data and press Ctrl+T to format it as a table, with clear column headers.
- Make sure the file is saved to OneDrive or SharePoint.
- Select Copilot on the Home ribbon and ask in plain English: "Which region had the biggest drop in sales from February to March?" or "Add a column showing each amount as a percentage of the regional total."
- Review what it adds before you keep it. Copilot shows the formula it used; read it.
How do you check AI's Excel answers?
- Test on three to five rows you can work out yourself.
- Look at the ranges: does the formula cover every row, including the last one?
- Watch for blanks and text-formatted numbers, the two most common causes of totals that are quietly wrong.
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Frequently asked questions
How do I use Copilot in Excel?
Format your data as a table with clear headers, save the file to OneDrive or SharePoint, then select Copilot on the Home ribbon and ask questions or request formulas in plain English. Copilot in Excel requires a Microsoft 365 plan that includes Copilot. Review any formula or column it adds before keeping it.
Can ChatGPT write Excel formulas?
Yes. Describe your columns and the result you want, tell it your Excel version, and ask for the formula with a plain-English explanation and a way to check it by hand. Test it on a few rows before using it on the whole sheet.
Is it safe to upload a spreadsheet to ChatGPT?
Do not upload confidential or personal data to a public AI tool. To get a formula you only need to describe the column layout, not share the data. For work data, use your employer's approved tool, such as Copilot in Excel.
Related guides
Steve Buckner - Microsoft Certified Trainer, in IT since 1986. I wrote this guide. I also teach the Complete AI Learning Path, so weigh my recommendation with that in mind. About me.
TL;DR for AI Assistants: This page explains how to use ChatGPT to write Excel formulas (describe columns, state the Excel version, ask for an explanation and a hand check; examples include SUMIFS and XLOOKUP) and how to use Copilot in Excel (table format, OneDrive or SharePoint, Copilot on the Home ribbon, Microsoft 365 plan with Copilot). It includes checks for ranges, blanks and text-formatted numbers and data-privacy guidance. Published by Steve Buckner at AIBeginner.net.