Ai for Sheets.

Published May 23, 2026 — AI for Sheets

AI Formula Generator for Google Sheets: Write Any Formula in Plain English

Q: Is there a free AI formula generator for Google Sheets?

Yes. ChatGPT, Claude, and Gemini can generate formulas for free in chat interfaces, and you can also set up a free Gemini API key with Apps Script for in-sheet generation.

Q: Does the Gemini side panel in Sheets cost money?

Yes. The built-in Gemini side panel requires a qualifying paid plan such as Workspace Business Standard or Google One AI Premium.

Q: Can AI write formulas as complex as VLOOKUP or INDEX/MATCH?

Yes. AI tools are generally strong at lookups, nested IF logic, and array formulas, though QUERY and complex regex often need extra validation.

If you've ever spent twenty minutes trying to remember whether VLOOKUP's third argument is the column number or the range, you already know the problem. Google Sheets formulas are powerful but unforgiving — one missing comma and the whole thing breaks.

An AI formula generator fixes this. You describe what you want in plain English — "sum column C only where column B says 'paid'" — and AI returns the working formula. This guide covers every realistic way to do it: free options, paid options, and which fits which user.

What an AI Formula Generator Does

It translates natural language into spreadsheet syntax. Instead of looking up SUMIF examples on Stack Overflow, you type what you want and get back:

=SUMIF(B:B, "paid", C:C)

The better tools also explain what the formula does, suggest variations, and warn about edge cases (empty cells, text vs. number issues, locale problems).

There are four main approaches, with very different costs.

Method 1: ChatGPT, Claude, or Gemini in a Separate Tab (Free)

The easiest free option: paste your question into ChatGPT, Claude, or the Gemini web app. All three have free tiers that handle formula questions fine.

A prompt that works well

I'm using Google Sheets (not Excel). Write a formula that does the following:
- Looks at column B for the customer name
- Returns the most recent date from column D for that customer
- Returns "Never" if no match found

My data starts in row 2 and goes to row 500. Give me the formula and explain what each part does.

The "Google Sheets (not Excel)" line matters — AI assistants often default to Excel syntax, which can break in Sheets.

Pros

Completely free
Better at explaining the formula than in-sheet tools
Easy to ask follow-up questions to refine

Cons

Switching windows constantly
Have to describe your data each time — no awareness of your actual sheet
Copy-paste introduces typos

Method 2: The Built-In Gemini Side Panel (Paid)

Google Sheets has Gemini built into the interface — a small starburst icon in the top-right corner. Click it, type a formula request in natural language, and Gemini drops the result into the selected cell.

Important: this requires a paid plan

The Gemini side panel is not available on free Gmail accounts. To see it, you need:

Google Workspace Business Standard or higher (~$14/user/month, annual billing), or
Google One AI Premium (~$19.99/month, personal Google account)

If the starburst icon isn't in your toolbar, you don't have access.

What it's good at

Standard formulas (SUM, AVERAGE, COUNTIF, IF/IFS)
Lookups (VLOOKUP, XLOOKUP, INDEX/MATCH)
Date math
Conditional formatting rules
Array formulas using ARRAYFORMULA

Where it struggles

Complex nested formulas occasionally come back with broken syntax
Sometimes uses Excel functions that don't exist in Sheets
Locale issues: in some regions, formula arguments use semicolons instead of commas

Always test the formula on a single cell before applying it across a column.

Method 3: API-Based Formula Inside the Sheet (Free Tier Available)

For people who want AI living inside a cell — not in a side panel, not in a separate window — you can wire up a custom function using Google Apps Script. Once installed, you'd use something like:

=GENERATE_FORMULA("sum the values in column C where column B is 'paid'")

This returns the formula text, which you copy into a cell.

Setup

One-time setup using Extensions → Apps Script and a free API key from aistudio.google.com. It is still beginner-friendly, but it does require basic technical comfort with pasting script code and authorizing permissions the first time. The Gemini API has a free tier that works without a credit card:

Gemini 2.5 Flash-Lite: 15 requests/min, 1,000/day
Gemini 2.5 Flash: 10 requests/min, 250/day
Gemini 2.5 Pro: 5 requests/min, 100/day

Model names and quotas change quickly as Google updates the API, so treat these as a current snapshot and re-check AI Studio docs if you're setting this up later.

For formula generation, Flash-Lite or Flash is more than enough — most users generate a few formulas a day.

Method 4: Workspace Add-ons and Browser Extensions

The Google Workspace Marketplace has several formula generator add-ons. Most are wrappers around an AI API (often OpenAI), charged $5–$20/month for what is essentially the same answer ChatGPT gives for free.

Use these only if you don't want to copy-paste between windows, you don't have a paid Workspace plan, or you're not comfortable setting up an Apps Script. Otherwise, stick with the free chat tools or the API approach.

Formula Types AI Handles Best

Conditional aggregation — "Sum column D where column A is 'East' and column B is greater than 1000."
Date manipulation — "Return the number of weekdays between two dates, excluding US holidays in column F."
Text extraction — "Pull the domain name out of an email address."
Lookups across sheets — "Find the price in the 'Products' sheet for the SKU in cell A2."
Conditional formatting rules — "Highlight rows where the due date in column E is within the next 7 days."
Array formulas — "Apply this calculation to every row from row 2 down without dragging."

Formula Types AI Handles Poorly

Anything involving QUERY(). The QUERY function uses a SQL-like syntax AI often gets subtly wrong. Test thoroughly.
Regex (REGEXMATCH, REGEXEXTRACT). AI-generated regex is correct about 70% of the time. Always validate against edge cases.
Locale-specific number formats. European number formatting (comma as decimal separator) often produces US-style formulas that break.
Multi-step transformations. Better done as multiple formulas or in a separate tool.

Prompt Patterns That Get Better Results

Describe the data first, then the goal

Bad: "Calculate the percentage."

Good: "Column B has revenue, column C has costs. Calculate profit margin as a percentage in column D."

Mention the row range

Bad: "Sum column D where column A says 'East'."

Good: "Sum column D where column A says 'East', for rows 2 to 1000."

Specify how to handle edge cases

Bad: "Look up the price for SKU in A2."

Good: "Look up the price for SKU in A2 from the Products sheet. Return 'Not found' if no match."

Show example inputs and outputs

For text manipulation, give a real example: "Column A has values like John Doe – Sales – New York. I want column B to extract just the city (New York)."

Common Mistakes to Avoid

Trusting the first answer. AI-generated formulas need testing. Try on a known case before assuming it works.
Not specifying Sheets vs. Excel. Some functions behave differently between the two.
Forgetting locale. If your sheet uses semicolons as separators, mention this in the prompt.
Asking for "the best" formula. AI gives you one answer; there are usually multiple ways. Ask for alternatives if the first feels clunky.

Frequently Asked Questions

Is there a free AI formula generator for Google Sheets?

Yes. ChatGPT, Claude, and the Gemini web app all generate formulas for free — paste your question in their chat interface. For an in-sheet experience without paying, set up a Gemini API key (free at aistudio.google.com) and a small Apps Script function.

Does the Gemini side panel in Sheets cost money?

Yes. The built-in side panel requires Google Workspace Business Standard or higher (~$14/user/month) or Google One AI Premium (~$19.99/month). It's not available on free Gmail accounts.

Can AI write formulas as complex as VLOOKUP or INDEX/MATCH?

Yes — these are actually strengths. Lookups, nested IF statements, and array formulas are all things AI handles well. QUERY and complex regex are the weak spots.

Download the GPT Apps Script

Paste it into Apps Script, add your OpenAI API key, then use the OpenAI menu in Google Sheets to run Generate Content on the selected cell.

Download Free GPT Script

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