How to Use ChatGPT Inside Excel and Google Sheets

OpenAI just launched ChatGPT as an add-on for both Microsoft Excel and Google Sheets, now powered by GPT-5.5. You describe what you need in plain English and it builds, analyses, or updates the spreadsheet directly inside the file. Here is how to set it up and what to use it for.

What You'll Need

A ChatGPT subscription (Business, Enterprise, Edu, Pro, or Plus outside the EU)
Microsoft Excel (desktop or web) or Google Sheets
The ChatGPT for spreadsheets add-on from OpenAI
Note: still in beta. VBA, macros, and some advanced features are not fully supported yet

Step 1: Install the Add-On

In Excel: Open Excel and go to the Insert tab. Click "Get Add-ins" and search for "ChatGPT." Install the official OpenAI add-in.

In Google Sheets: Open a sheet and go to Extensions → Add-ons → Get add-ons. Search for "ChatGPT" and install the official OpenAI add-on.

Once installed, you will see a ChatGPT panel on the right side of your workbook. Sign in with your OpenAI account.

Step 2: Build a Spreadsheet From Scratch

With the panel open, type a request in plain language. ChatGPT reads your cells, formulas, tabs, and structure, and works directly in the file rather than a separate window.

Try using this base prompt:

Create a monthly budget tracker with columns for category, budgeted amount, actual spend, and variance. Add rows for rent, utilities, marketing, salaries, and software subscriptions. Include a total row with SUM formulas.

ChatGPT builds the spreadsheet, adds the formulas, and formats it. You can then edit normally or ask it to adjust.

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Customisation: change the categories, currency, or layout in the same prompt. "Use GBP," "add a column for notes," "format the total row in bold" all work.

Step 3: Analyse Existing Spreadsheets

You do not need to start from scratch. Open any existing workbook and ask ChatGPT to work with what is already there.

Add a column that calculates the percentage change between this month and last month for each row

Summarise the key numbers from the Sales tab in a new summary sheet

Find any cells with errors and explain what is causing them

Create a pivot-style breakdown of revenue by region from the data in Sheet1

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Customisation: eference specific tabs, columns, or cell ranges in your prompts. The more specific you are about where the data is, the better the results.

Step 4: Clean Messy Data

GPT-5.5 handles messy spreadsheets better than the previous model. Use it to normalise inconsistent data without writing a single formula.

Try these ideas for inspiration:

The dates in column B are in three different formats. Convert them all to DD-MM-YYYY.

Standardise the company names in column A. "Acme Corp", "ACME corporation", and "acme" should all become "Acme".

Split the full names in column C into separate first name and last name columns.

This is the kind of task that used to mean Power Query, regex, or 30 minutes of manual cleanup. Now it is a sentence.

Step 5: Run Scenarios and What-If Analysis

ChatGPT can model different outcomes without manually rebuilding formulas.

Try this:

Using my current budget, show me what happens if marketing spend increases by 20% and revenue stays flat. Create a new tab called Scenario 2 with the adjusted numbers.

If we hire two more people at £45,000 each, what does that do to our monthly burn rate? Update the headcount row and recalculate the totals.

Useful for board prep, investor updates, or simply understanding how changes affect your bottom line.

Step 6: Get Explanations and Fix Errors

If you inherit a spreadsheet with complex formulas, ChatGPT can explain what they do and fix issues.

Try this:

Explain what the formula in cell D14 does in plain English

I'm getting a #REF! error in the Forecast tab. Find what is causing it and fix it.

Simplify the nested IF formula in column E so it is easier to understand and maintain

Especially useful when working with spreadsheets built by someone else, or revisiting models you built months ago.

Real-World Applications

Finance and Accounting

Build financial models, run scenario analysis, and clean inconsistent data without switching between tools. Useful for budgeting, forecasting, and investor reporting.

Sales and Operations

Create pipeline trackers, commission calculators, and inventory reports from plain-language descriptions. Update them weekly by asking ChatGPT to refresh the numbers from a data source.

Marketing

Track campaign spend, calculate ROI across channels, and build comparison tables. Ask ChatGPT to summarise performance across tabs and highlight what changed.

Small Business Owners

Build budgets, invoices, and expense trackers without knowing Excel or Sheets formulas. Describe what you need and let ChatGPT handle the structure and calculations.

Next Steps

Start with something you already have. Open a spreadsheet you use regularly and ask ChatGPT to improve it. Add a summary, fix a formula, clean a column, or create a new view of the data.

Start with these prompts:

Look at this spreadsheet and suggest three improvements to the structure or formulas

Create a dashboard tab that summarises the key numbers from all other tabs in this workbook

Build a monthly P&L template with revenue, cost of goods, operating expenses, and net income. Include formulas for gross margin and net margin percentages.