How to use AI function in Google Sheets and trust the results

Google Sheets lets you type a prompt straight into a cell and get an answer back. Learning how to use AI function in Google Sheets takes only a few minutes, but trusting the output takes a little more care. You can use either =AI() or =Gemini() as the function name. Google's Help Center lists the feature under Workspace Experiments, so it may not appear in every account yet.

This guide covers the setup, a prompt pattern that returns clean cells, and a routine for checking the results. It also explains when an ordinary formula is the better pick, which most people learn the hard way.

Enter the function in a cell

Open a spreadsheet in Google Sheets on your computer and click an empty cell. Type =AI( or =Gemini( and write your prompt inside quotation marks. Google's instructions then say to click Insert. Because the feature is still labelled an experiment, buttons and wording can change, so check the Help Center page if your screen looks different.

=AI("Summarize this comment in five words or fewer.", B2)

The first part is your instruction. The second part points at the cell holding the text to work on. Treat this pattern as a starting point and read the Syntax section of Google's Help Center page to confirm the details for your version. Put the formula in the first row, test it, and then copy it down.

Fill a whole column with one prompt

Here is how to use AI function in Google Sheets on many rows at once. Google's Help Center describes two shortcuts: adding an AI column to a table and filling columns with Gemini. Both save you from copying a formula down by hand. They suit jobs like sorting comments into groups, writing short summaries, or translating a column of product names.

If your data sits in a plain range instead, the copy-down method works just as well. Messy rows give messy answers, so tidy the input first. Our guide to cleaning spreadsheet data covers the habits that carry over to Sheets.

Write prompts that return one clean answer

Vague prompts give you rambling cells. Ben Collins, in his guide to three ways to use AI tools with Google Sheets, lists five habits for good prompts. Give context, be specific, include example inputs, state clear instructions, and describe the output you want. Applied to a cell, those habits produce a prompt like this one.

=AI("You are cleaning survey data. Read the comment and reply with only one word: Positive, Negative or Neutral.", B2)

Notice what the prompt does. It names the job, limits the answer to three words, and says nothing else should appear. That last rule keeps extra sentences out of your column, so counts and filters work later. Before you copy the formula down, test it on three or four rows you can judge yourself.

When a regular formula beats AI

Use AI for judgement and language. Use ordinary formulas for arithmetic and exact matching. Knowing how to use the AI function in Google Sheets also means knowing when to skip it. TechRepublic's walkthrough of Gemini in Google Sheets points out that two people who enter the same prompt may not get the same response, which is a poor fit for any cell that feeds a report.

A quick test helps. If you can write the rule in one line, use a formula. If the rule is "it depends what the comment means", use AI. Fixed rules are easier to audit, and they stay stable when you reopen the file next month. When you want one formula to fill a whole column, array formulas in Google Sheets do that for ordinary functions.

Check every AI result before you rely on it

Treat each AI cell as a draft. TechRepublic shows why with two examples. A Gemini prompt for all 50 U.S. states returned a table of only 40. A formula request first returned a COUNTIF that threw an error, and a second prompt gave a COUNTIFS that worked after some tweaking. Build a short review into your routine:

• Read ten rows yourself and compare each answer with the source text.
• Count each category and check that the total matches your row count, using the formulas below.
• Fix the prompt, not the cells, when the same mistake repeats.
• Copy the approved column and use Paste special, then Values only, so the answers sit as plain text and no longer depend on the formula.
• Keep the prompt wording in a note beside the sheet so a colleague can repeat the work.

=COUNTIF(C2:C101,"Positive")+COUNTIF(C2:C101,"Negative")+COUNTIF(C2:C101,"Neutral")
=COUNTA(B2:B101)

If the first result does not match the second, some cells contain stray wording or errors. Also remember that the text in your cells goes to an AI model. Before you run customer names, health details or financial records through it, check your organisation's data policy. TechRepublic notes that people on work or school Workspace accounts may need an administrator to grant access to Gemini.

Other ways to bring AI into a sheet

If the function is not available to you, Ben Collins describes three other routes: chatbots such as ChatGPT or Bard (which Google has since renamed Gemini), add-ons, and the API with Apps Script. A chatbot is the easiest start. Describe the job clearly, ask for a formula, and paste the result into your cell. His example asks for a formula that extracts a phone number from a text string and includes a sample string in the prompt.

Add-ons such as GPT for Sheets and Docs put AI formulas inside the sheet, although you need an OpenAI API key to use it. The API and Apps Script route is the advanced one, and the key works like a password, so keep it private. TechRepublic also covers the Ask Gemini panel in Sheets, where you can describe a table and have Gemini build it.

If you would rather describe the result and skip the syntax, Formula Foundry's AI formula generator writes the formula for you. You still paste it in and test it on a handful of rows you can check by eye.

Action steps

1. Try one cell: Type =AI() or =Gemini() in an empty cell, add a short prompt and a cell reference, and confirm with Insert as Google's Help Center describes.
2. Tighten the prompt: Give context, name the job, and limit the answer to a few set words so the column stays clean.
3. Test a few rows: Run the formula on three or four rows you can judge yourself before copying it down.
4. Run the count check: Use COUNTIF and COUNTA to confirm every row holds an expected answer.
5. Lock the approved answers: Copy the column and paste it back as values only, then keep your prompt wording in a note.

Frequently asked questions

Should I type =AI() or =Gemini()?

Google's Help Center says you can use either name in a cell. Pick one and use it consistently so your colleagues can read the sheet.

Why can't I see the AI function in my account?

Google lists the feature under Workspace Experiments, so availability can depend on your account. If you use a work or school account, ask your Workspace administrator what is enabled.

Will the same prompt always give the same answer?

Not necessarily. TechRepublic notes that two people entering the same Gemini prompt may receive different responses, so check the output and paste approved answers as values.

Can I use the AI function for totals and lookups?

You can, but ordinary formulas such as SUM, COUNTIF and lookups give the same answer every time. Save AI for tasks that depend on meaning, such as grouping comments or summarising text.