Claude for Excel

Full review

Claude for Excel is Anthropic’s add-in for Microsoft Excel. It sits in a sidebar next to your workbook and reads and changes the cells, formulas and sheets you have open.

Code-level interaction

Claude reads your spreadsheet structurally: it follows cell references, sees which formulas depend on which inputs, and changes data without breaking those links. You can ask it to:

• Write complex formulas and explain them
• Walk you through how a number was calculated, with links that jump to the cells it used
• Change an assumption and update everything that depends on it (“Change the discount rate to 8%”)
• Find the root cause of a #REF! or #DIV/0! error
• Build a new model from a description, or fill in a template you already have
• Sort, filter, edit pivot tables, and add conditional formatting and dropdown lists

It warns you before it overwrites existing data. What it can’t do: macros, VBA and Excel’s data tables.

What changed since I first reviewed it

Anthropic has kept shipping. The add-in is now generally available on every paid plan, Pro included, in Excel on Windows, on the Mac and on the web. Four changes matter most:

One conversation across Office. If you also have the add-ins open in PowerPoint, Word or Outlook, Anthropic says Claude can read from one app and write in another: build a model in Excel, ask for a summary deck in PowerPoint, and it works from the model instead of you explaining it again. It only works with files that are open, and it can’t open or switch files on its own. On Pro and Max this is on by default (the setting is called “Let Claude work across files”); on Team and Enterprise plans, an admin has to allow it.

Skills. The skills you’ve enabled in your Claude account work here too. Claude applies them when they fit, or you type / in the sidebar and pick one. If your team has a skill for how financial models are built, the add-in can use it.

Connectors. You can pull in outside context from the sidebar. For finance, Anthropic names S&P Global, LSEG and Daloopa; your company can add its own.

Standing instructions. In the add-in’s settings you can write preferences that apply to every conversation, such as “thousand separators, always” or your currency. They apply in Excel only.

What it knows about the rest of your work

What I’d find most useful is to start something in Excel or PowerPoint and have Claude bring in the knowledge and instructions from my other projects. Today that works partly. According to Anthropic’s documentation, two things come along from your Claude account: skills and connectors. Your projects in the Claude app, Claude’s memory, your chats and Cowork’s instructions aren’t mentioned, so I’d assume they stay behind. Chat history in the add-in is stored in your browser on that computer and doesn’t sync.

So if you want the add-in to know how you work, write it down as a skill. Skills come along into every add-in.

Where it fits next to Cowork and Claude Code

To build a new workbook from scratch, I’d probably start in Claude, in Cowork or Claude Code. That’s how The Budget was made: Claude Code wrote code that produces the file, all 3,303 formulas of it. To keep working on a workbook, or to change one that already exists, I’d open it in Excel and use Claude there. Anthropic’s own Cowork course suggests the same split: Cowork for the first version, the add-in for refining it in the app.

Before you use it at work

At work, it’s an add-in like any other: your company decides whether you get it. IT can deploy it to everyone through the Microsoft 365 admin center. Companies that run Claude through Amazon Bedrock, Google Cloud Vertex AI or Microsoft Foundry can use it without individual Claude accounts, but then without the cross-app feature, and possibly without skills and connectors.

Two details for whoever approves it: the add-in doesn’t inherit custom data retention settings your organization has set, and its activity doesn’t appear in Enterprise audit logs. Anthropic also warns that files from outside, such as downloaded templates, vendor spreadsheets or data imports, can contain hidden instructions that try to steer Claude. Use it on files you trust, and read the confirmation when it asks before a risky step.

The token cost reality

The main downside is token consumption. Because Claude needs to read and understand your worksheet structure, large spreadsheets consume tokens quickly, and the add-in draws on the same usage limits as the rest of your Claude account. On a Pro subscription ($20/month), you may find yourself hitting limits during intensive sessions. Max subscribers ($100-200/month) get substantially more headroom, but heavy Excel users should factor this into their subscription choice.

Who should use Claude for Excel

Knowledge workers who spend significant time in Excel — analysts, finance professionals, operations teams, and anyone who regularly works with complex spreadsheets. The productivity gains are real, but be mindful of token usage on lower-tier plans. If you mostly build new workbooks from scratch, I’d probably start in Cowork or Claude Code instead; the add-in is for working on the ones you have.