Claude for Excel: Explain, Clean Up and Fix a Spreadsheet Inside Excel

Ask "how is this number calculated?" and get an answer that links to the exact cells, then let Claude fix the broken formula, after you say yes.

Checked October 19, 2026. Researched and drafted with help from Grok Bot.

Quick answer

• Claude for Excel is an add-in that puts Claude in a side panel inside Excel. It reads your open workbook and can make changes.
• What it's great at: explaining formulas with clickable cell citations, finding the cause of #REF! and #DIV/0! errors, changing an assumption while keeping formulas intact, and native jobs like sorting, filtering, pivot tables, conditional formatting and dropdowns.
• Plans: Claude Pro, Max, Team or Enterprise. Not Free.
• Where it runs: Excel on the web, Windows (Microsoft 365) and Mac (16.46+). Not Excel 2016/2019, iPad or Android.
• It asks before risky changes and warns before overwriting data. Still, work on a copy.

What to ask Claude for Excel

Is it worth it? The verdict

Quick questions

Does it cost extra? No. It comes with Claude Pro, Max, Team and Enterprise, and uses your normal Claude limits.

Can it run macros? No. Anthropic lists macros/VBA and data tables as unsupported.

Where is my chat history kept? In your browser, on your device. Anthropic says it isn't stored on its servers or synced across devices. You can clear it in the add-in's Settings.

Can I set rules like "always use dollar signs"? Yes. In the add-in sidebar, open Settings and use Instructions. These apply to every Excel chat (not Word or PowerPoint).

Is it safe with files from other people? Be careful. Anthropic warns that downloaded templates and vendor files can hide instructions that try to trick Claude. Use it on spreadsheets you trust, and read every confirmation.

Before you start

• Plan: Claude Pro, Max, Team or Enterprise.
• Excel version: Excel on the web; Windows with a Microsoft 365 subscription (build 16.0.13127.20296 or later); or Mac 16.46 or later.
• Make a copy of the workbook first (File → Save a Copy or Save As). Anthropic recommends starting from a trusted copy before wide edits.
• Work account? Your IT admin may need to deploy the add-in for you.

Step 1: Install the add-in (5 minutes)

1. Go to the Claude for Microsoft 365 listing on Microsoft AppSource.
2. Select Get it now.
3. Open Excel and activate the add-in: Home → Add-ins on Windows, or Tools → Add-ins on Mac.
4. Sign in with your Claude account.

Step 2: Set your Instructions (2 minutes)

In the add-in sidebar, open Settings → Instructions and add your preferences, for example:

Use US dollars with 2 decimals and thousand separators. Bold column headers. Explain things in plain English, no finance jargon. Ask before changing more than 20 cells at once.

Step 3: Ask, check, approve

1. Ask your question in the side panel.
2. Click the cell citations in the answer to jump to each cell.
3. When Claude proposes a change, read it. For risky operations, it asks you to confirm before it runs.
4. Check the result. Use Undo in Excel if needed.

Try it: 3 worked jobs

1. Understand a household budget someone else built

Explain this workbook to me like I'm new to spreadsheets. What does each tab do? How is "Money left over" on the Summary tab calculated? Link to the cells.

What good looks like: a short tour of each tab, then a step-by-step trace of the "Money left over" cell with clickable links.

2. Fix a broken sales sheet

The Summary tab shows #REF! in B12 and #DIV/0! in D15. Find the root cause of each, explain it in one sentence, and suggest a fix. Don't change anything until I say yes.

What good looks like: "B12 points to a column that was deleted on the Sales tab" and "D15 divides by an empty month," each with a proposed formula. You say yes, Claude fixes them, and you spot-check the totals.

3. Clean up a messy bank or app export

On the Export tab: remove blank rows, split the "Date Time" column into Date and Time, make Amount a number with 2 decimals, sort by date, and add a dropdown in a new Category column with: Groceries, Bills, Dining, Transport, Other. Then highlight any amount over $200.

What good looks like: a tidy table with a Category dropdown and highlighted big spends, done with Excel's own sort, data validation and conditional formatting.

Safety checklist for files from others

• Is the file from someone you trust?
• Are you working on a copy?
• Did you read each confirmation before saying yes?
• Did you avoid uploading highly sensitive or regulated data without controls?
• Did you spot-check 2–3 numbers by hand?

Common mistakes and fixes

Prompt pack

What are the 5 most important formulas in this workbook, and what does each one do?

Check this sheet for errors, inconsistent formulas and hard-coded numbers that should be formulas. List them; don't fix yet.

Make a pivot table of total Amount by Category and Month on a new tab.

Add a chart that shows monthly spending, and explain what it shows in 2 sentences.

What would happen to the total if rent went up 5%? Show the change without overwriting my original numbers.

Same job in other chatbots

Next level

• Claude Cowork: Hand Off a Project (Advanced): get a finished Excel workbook and PowerPoint deck back from a goal and a folder.
• Make Real Word, Excel, PowerPoint and PDF Files With Claude (coming soon).