Free Options Excel + AI 7 min read

Best AI for Excel in 2025: From Formulas to Full Analysis

Microsoft Copilot in Excel ($30/mo, native), ChatGPT (formula help + Code Interpreter file upload), Claude (complex formula explanations), Gemini in Sheets (free), Formula.dog (10 formulas/day free), Formulabot (formula + explanation) — compared by use case and price.

1. Microsoft Copilot in Excel — Best for full Excel integration

If you live in Excel and your organization is already on Microsoft 365, Copilot is the most seamless AI experience available. No copy-paste, no switching tabs — it works directly inside your worksheet.

Microsoft Copilot in Excel — $30/user/month

Native Excel Microsoft 365 Business

Best if: you are a heavy Excel user in a corporate environment already on Microsoft 365 Business Basic or above.

Click the "Copilot" button in the Excel ribbon, type in natural language, and Copilot adds formulas, creates pivot tables, generates charts, and explains data — all directly on your worksheet. No exporting your data, no pasting results back in. Commands like "analyze this data and highlight key trends", "create a pivot table showing sales by region", or "add a formula that calculates YoY growth" execute in place.

Pros
  • Works directly in Excel — no copy-paste
  • Pivot tables, charts, formulas in plain English
  • Data stays in your worksheet
  • Explains data trends inline
Cons
  • Requires Microsoft 365 Business plan
  • $30/user/month is significant
  • Not available on personal/home plans
vs ChatGPT: Copilot works directly in Excel — you do not need to export or import anything. For heavy Excel users, this workflow difference alone justifies the cost over ChatGPT.

2. ChatGPT (OpenAI) — Best for formula help + data analysis via Code Interpreter

ChatGPT covers two distinct use cases: free formula generation via the chat interface, and paid file upload analysis via Code Interpreter in the Plus tier.

ChatGPT — Free / $20/mo Plus

Free tier $20/mo Plus

Best if: you need formulas written or explained without a Microsoft 365 subscription, or you want to upload a spreadsheet and ask questions about it.

Formula help (free tier)

Describe what you want: "write an Excel VLOOKUP formula that looks up employee ID in column A and returns salary from column C" — ChatGPT returns the exact formula with an explanation. Copy it into your cell. Works for VLOOKUP, INDEX/MATCH, SUMIFS, nested IFs, dynamic arrays, and more.

Code Interpreter (Plus, $20/mo)

Upload your Excel or CSV file directly. ChatGPT analyzes the data, generates Python-powered charts, calculates statistics, identifies outliers, and exports results. Ask "what are the top 5 customers by revenue?" or "show me month-over-month growth as a chart" — it runs code and returns the output.

Pros
  • Formula generation is free
  • Code Interpreter handles complex analysis
  • Upload Excel/CSV and ask questions
  • Generates charts from your data
Cons
  • Requires copy-paste — not native Excel
  • File upload needs $20/mo Plus
  • GPT-4o free tier has usage limits

3. Claude (Anthropic) — Best for understanding complex formulas + data design

Claude excels at explanation — not just writing formulas but breaking down inherited formulas you do not understand, debugging errors, and advising on spreadsheet architecture.

Claude — Free / $20/mo Pro

Free tier $20/mo Pro

Best if: you need to understand complex inherited formulas, debug errors, or get architectural advice on how to structure a spreadsheet.

Formula explanation

Paste a complex nested formula and ask "explain what this formula does step by step." Claude breaks down each nested function — better than ChatGPT for deeply nested IF/VLOOKUP/INDIRECT combinations that even the original author may not fully remember.

Error debugging

Paste a formula returning #REF!, #VALUE!, or #N/A — Claude explains exactly why the error occurs and provides the corrected formula with an explanation of what changed.

Data structure design

Ask "I need to track sales by region and salesperson, how should I structure this spreadsheet?" — Claude gives architectural advice on column layout, normalization, and formula design before you build anything.

Pros
  • Best formula explanation of any AI
  • Error diagnosis with corrected output
  • Spreadsheet architecture advice
  • Free tier available
Cons
  • No native Excel integration
  • Requires copy-paste workflow
  • No file upload on free tier

4. Google Gemini in Sheets — Best free AI in spreadsheets

For teams already on Google Workspace who can work in Sheets instead of Excel, Gemini provides a free Copilot-like experience without any subscription cost.

Google Gemini in Sheets — Free (Google Workspace)

Free Google Sheets

Best if: your team already works in Google Workspace and you want free AI assistance in your spreadsheets without switching to Excel or paying for Copilot.

In Google Sheets, click the "Ask Gemini" sidebar and type your request. Gemini creates formulas from plain English descriptions, analyzes data ranges, and suggests improvements — all without leaving your spreadsheet. Most Google accounts qualify for Gemini Flash in Sheets at no extra cost.

Pros
  • Free with most Google accounts
  • Works natively inside Google Sheets
  • Formula generation + data analysis
  • No copy-paste required
Cons
  • Google Sheets only — not Excel
  • Some advanced Excel features differ
  • Requires Google Workspace account

5. Formula.dog — Best free formula generator

Formula.dog is a single-purpose tool: describe a formula in plain English, get the exact formula back. No chat interface, no setup — just formulas.

Formula.dog — Free (10/day) / $4.99/mo

Free tier $4.99/mo unlimited

Best if: you need formulas written quickly without opening a full chat interface, and 10 formulas per day is enough for your workflow.

Describe what you want — "give me a formula that counts cells in column B that are greater than 100 and have 'Approved' in column C" — and Formula.dog returns the exact formula. Supports Excel, Google Sheets, and Airtable. The free tier gives 10 formulas per day, which is sufficient for most users. At $4.99/mo for unlimited, it is the cheapest paid option in this guide.

Pros
  • 10 formulas/day free
  • Supports Excel, Sheets, Airtable
  • Fastest workflow for formula-only needs
  • $4.99/mo for unlimited
Cons
  • Formula generation only — no analysis
  • No formula explanation mode
  • 10/day limit on free tier
vs ChatGPT: Formula.dog is simpler and faster for formula-only use cases. ChatGPT is better when you also need explanation, complex analysis, or multi-step reasoning about your data.

6. Formulabot — Best for AI formula + explanation combo

Formulabot combines formula generation, formula explanation, and a basic AI data analyst in one spreadsheet-specific tool — a middle ground between Formula.dog and ChatGPT Plus.

Formulabot — Free (limited) / $6.99/mo Pro

Free tier $6.99/mo Pro

Best if: you want a spreadsheet-specific AI tool that handles both formula generation and formula explanation without using a general-purpose AI chat interface.

Explanation mode

Paste any complex formula and Formulabot explains it in plain English — useful for understanding inherited spreadsheets where you do not know what the formulas do.

AI Analyst (Pro)

Upload a spreadsheet and ask questions in natural language. Formulabot returns insights without requiring Python knowledge or a ChatGPT Plus subscription.

Pros
  • Generate + explain formulas in one tool
  • AI Analyst for file upload
  • Spreadsheet-specific — better focused than ChatGPT
  • Free tier available
Cons
  • Limited free tier
  • Less powerful analysis than ChatGPT Code Interpreter
  • Smaller community than general AI tools

Comparison by use case

Use Case Best Tool Free?
Full Excel integration Copilot in Excel ✗ ($30/mo)
Formula generation Formula.dog or ChatGPT ✓ Free tiers
Upload + analyze data ChatGPT Code Interpreter ✗ ($20/mo)
Explain complex formulas Claude or Formulabot ✓ Free tiers
Google Sheets AI Gemini in Sheets ✓ Free
Spreadsheet-specific AI Formulabot ✓ Free tier

Decision guide: which AI for Excel should you use?

Corporate Excel user on Microsoft 365? — Microsoft Copilot in Excel. Works directly in cells, no copy-paste, no exporting. The $30/mo is justified if you use Excel 8+ hours a week.
Just need formulas written quickly for free? — Formula.dog (10/day free) or ChatGPT free tier. Describe what you want, paste the result.
Need to upload a spreadsheet and analyze it? — ChatGPT Plus Code Interpreter ($20/mo). Upload the file, ask questions in natural language, get charts and statistics back.
Have a complex formula you inherited and don't understand? — Claude (explain step by step, free) or Formulabot (dedicated formula explainer). Both are free on their base tiers.
Working in Google Sheets? — Gemini in Sheets. Free with most Google accounts, works natively inside Sheets the same way Copilot works in Excel.
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Monitor ChatGPT and Microsoft Copilot status

When ChatGPT or Microsoft Copilot goes down mid-spreadsheet session, you want to know immediately so you can switch tools instead of troubleshooting your formulas. Track both at prismix.dev.

FAQ

What is the best AI for Excel formulas?

For free: ChatGPT (describe what you want, paste the formula), Claude (explain complex formulas), or Formula.dog (10 formulas/day free). For full Excel integration: Microsoft Copilot in Excel ($30/user/mo with Microsoft 365) works directly in your worksheet without copy-paste.

Can AI write Excel formulas?

Yes. Describe what you want the formula to do in plain English, and tools like ChatGPT, Claude, Formula.dog, or Formulabot generate the exact Excel formula to copy into your cell. They handle VLOOKUP, INDEX/MATCH, SUMIFS, nested IFs, dynamic arrays, and more.

Can AI analyze my Excel data?

Yes. ChatGPT Plus Code Interpreter ($20/mo) lets you upload an Excel or CSV file and ask questions like "what are the top 5 customers by revenue?" — it runs Python code and returns charts and tables. Microsoft Copilot in Excel does this natively without uploading.

Is Microsoft Copilot worth $30/month for Excel?

For heavy Excel users (8+ hours/week) in corporate environments, yes. It eliminates copy-paste workflow and works directly in cells. For casual users, ChatGPT free tier for formula help is sufficient.