Is there an AI for writing excel formulas?

Copilot in Excel: what Excel's own AI does with formulas

Copilot in Excel is the assistant built into Excel. Ask in plain words and it writes a single-cell formula, or a whole new column or row of formulas calculated from your existing data, and explains how each one works. It can also apply formulas across several sheets, build PivotTables and charts, and change the workbook directly instead of only suggesting.

It comes with a Microsoft 365 subscription: Personal at $9.99 a month, Family at $12.99 (Copilot for the subscription owner only) and Premium at $19.99, Personal and Family with monthly AI credits that can run out on heavy use, Premium with higher limits. At work it is a paid add-on, Copilot Business, at $21 per user a month on a yearly plan ($18 for the first year if you sign up by December 31), on top of a Microsoft 365 business plan.

How to use Copilot in Excel to write a formula you can trust

Click the Copilot icon in the lower-right corner of Excel. It opens in edit mode, which changes the sheet directly; switch to plan mode to approve the approach first, or to chat mode to get an answer without touching the workbook. Name the columns in your request, as in "add a column that divides Revenue by Units": Microsoft's own tip is that naming them gives more accurate results.

Then check it like a colleague's work. Read the explanation, test the formula on rows where you already know the answer, and try the edge cases: a blank cell, a zero, a duplicate, a date typed as text. The same habit applies to every tool above. If there is no Copilot icon at all, it isn't part of your subscription or your organization has switched it off.

Excel formula generator: inside the workbook or in a browser tab

An Excel formula generator comes in two kinds. The browser kind turns your description into a formula you paste back; the one above gives you 5 free runs a day plus 50 credits a month, then costs $9 a month, and also writes Google Sheets formulas, VBA and other scripts. The other kind works inside the workbook: Excel's own assistant and the add-ins above read your real headers and put the formula in the cell.

The browser kind only knows what you tell it. It can't see that your headers start in row 3, that a column holds numbers stored as text, or that the sheet name has a space in it, so most of its wrong answers are about your layout, not about Excel. Give it the column letters, the header names, a few sample rows and the result you expect for one of them.

Excel formula not calculating or not working: what AI can and can't see

Check three things before you rewrite anything. Calculation may be set to Manual: switch it back under Formulas, Calculation Options, Automatic (in the desktop app the setting covers every open workbook, and F9 recalculates by hand). If you see the formula instead of its result, Show Formulas may be on, and Ctrl+` turns it off. Numbers stored as text cause the same symptom; Excel marks them with a green triangle that offers Convert to Number.

This is where AI helps less than you would think. A formula pasted into a chat window carries none of those settings, so a chatbot will happily rewrite a formula that was never broken. For real errors like #N/A, #REF! or #VALUE!, an assistant inside the workbook can trace the cell back to its source; ask it for the cause, not for a new formula. Outside Excel, paste the formula, the error and a few rows, and ask what each part returns.

writing excel formulas: quick answers

What is the best AI for Excel?

For formulas, the one that works inside your workbook, because it reads your real columns instead of your description of them. If you already pay for Microsoft 365, that is Excel's own assistant, the first pick above. If you don't, one of the add-ins above works inside Excel on a free plan with limited use. For charts and patterns in the numbers rather than formulas, see AI that analyzes spreadsheet data.

Is there an AI add-in for Excel that writes formulas?

Yes. The two chatbot add-ins above install from the Add-ins button in Excel and write, explain and fix formulas in the open workbook. One works on its free plan with limited use; the other needs its $20-a-month plan and runs in Excel for the web, Windows and Mac, but not in Excel 2016 or 2019 bought outright, on iPad or on Android. Neither is built for VBA macros.

What happened to the COPILOT function in Excel?

Microsoft removed it. The =COPILOT function ran an AI prompt inside a cell, never left the Frontier and Insider preview programs, and has not been available in Excel since September 14, 2026. The same requests now go through the Copilot pane, which writes ordinary formulas that give the same result every time they recalculate.

Can AI explain an Excel formula someone else wrote?

Yes. Paste the formula, or select the cell in an assistant that works inside Excel, and ask for a walkthrough: what each range points to and what each nested function returns. At least one add-in above links its answer to the exact cells, so you can click through and check. Ask for the explanation before you inherit a formula, and the catch above gets smaller.

Can AI write VBA macros for Excel?

Yes, but you install them yourself. Chatbots and the browser generator above write VBA from a description, while the add-ins that work inside Excel are not built for macros. Paste the code into the VBA editor in the desktop app, because Excel for the web can't create, run or edit VBA, and run it on a copy first: Excel's Undo does not reverse what a macro changed.