AI in Excel: formulas, clean data, checks

You can use AI in Excel to write and explain formulas, clean up messy data and spot patterns, as long as you describe your sheet clearly and test every answer on rows you can check by hand. You do not need to code, and you do not need a special add-in to start.

This guide shows the tasks where AI saves the most time in a spreadsheet, how to ask for them, and how to check the results before anyone relies on them.

Key facts about our free AI workshop

• Free, live on Zoom, every weekend
• 3 hours, 12:00-15:00 SAST (10:00-13:00 UK, 11:00-14:00 CET), on Saturday or Sunday (you pick one)
• ChatGPT, Claude and Gemini on your own work
• No coding needed

How can AI help with Excel?

Most people use AI in Excel for four jobs:

• Writing formulas. Describe what you want in plain words and get a formula back.
• Explaining formulas. Paste in a long nested formula someone else wrote and ask what each part does.
• Cleaning data. Get steps or formulas to split names, fix dates, remove duplicates and standardise text.
• Reading the numbers. Ask what stands out in a summary table, then check whether it is true.

You can do this with a chatbot such as ChatGPT, Claude or Gemini in another window, or with Copilot inside Excel if your employer provides it. Our guide to Microsoft Copilot covers the built-in option.

How do I ask AI for an Excel formula?

Describe the sheet as if to a colleague who cannot see it:

1. Name the columns and what is in them: "Column A has invoice dates, column B has customer names, column C has amounts in rand."
2. Say where the answer should go and what it should show: "In F2, the total for the customer named in E2, for March only."
3. Say which version of Excel or Google Sheets you use, because some functions are not in older versions.
4. Ask for a one-line explanation of how the formula works.

A vague request like "sum by customer" gets a generic answer. A clear description usually gets a working formula the first time.

The quickest way to get good at this is to do it live, with someone answering your questions. Our free workshop runs every weekend on Zoom, 12:00-15:00 SAST (10:00-13:00 UK, 11:00-14:00 CET). Save my free seat.

How do I check a formula AI gives me?

Treat every formula as a draft until it passes three tests:

• A known answer. Pick two or three rows where you can work out the right result by hand, and compare.
• The edges. Try a blank cell, a zero, a date at the end of the month and a name spelt slightly differently.
• The explanation. If you cannot follow the explanation, ask again for a simpler formula. A formula nobody on the team understands is a risk the day it breaks.

Can AI clean up messy spreadsheet data?

Yes, and this is often where it saves the most time. Describe the mess and the result you want, for example: "Names are in one column as 'Surname, First name' with extra spaces. I want first name and surname in two columns, with the spaces removed." Ask for a formula or step-by-step instructions you can follow, rather than pasting a large sheet into a chatbot.

Keep a copy of the original data before you change anything, so you can compare and undo.

Is it safe to paste spreadsheet data into a chatbot?

Often it is not necessary. To get a formula, you only need to describe the columns, or paste five made-up rows with the same layout. Leave out names, ID numbers, salaries, bank details and client figures unless your employer has approved the tool for that data. In South Africa, personal information is covered by the Protection of Personal Information Act (POPIA). This is general information and not legal advice, so check your company's policy first. Our guide to POPIA and AI at work explains more.

What should I practise first?

1. Take a formula in a sheet you use often and ask AI to explain it line by line.
2. Ask for a simpler version that does the same job, and test both on the same rows.
3. Describe one cleaning job you do by hand every month and ask for the steps.
4. Save the prompts that worked in a note for next time.

What does the free workshop cover?

Over three hours on Zoom you work through choosing the right tool, writing prompts that work, researching and drafting quickly, getting answers from your own documents, making images and slides, building your own AI assistant, automating a repetitive task, making a simple web app without code, and understanding AI agents. You leave with a 30-day plan. Our hosts have taught more than 12,000 people.

It runs every weekend, on Saturday and again on Sunday, so you can pick the day that suits you. The times are set for South Africa, and the UK and Europe times above work for learners there too.

The quickest way to get good at this is to do it live, with someone answering your questions. Our free workshop runs every weekend on Zoom, 12:00-15:00 SAST (10:00-13:00 UK, 11:00-14:00 CET). Save my free seat.

Frequently asked questions

Can ChatGPT write Excel formulas?

Yes. ChatGPT, Claude and Gemini can all write and explain Excel formulas if you describe your columns and the result you want clearly. Test every formula on rows you can check by hand.

Do I need Copilot to use AI with Excel?

No. You can describe your sheet to any AI chatbot and paste the formula it gives you into Excel. Copilot only adds the option of asking from inside the app.

Do I need to know how to code?

No. You describe what you want in plain language, and the skills carry over to every AI assistant.