Write and understand spreadsheet formulas

What AI actually does here

• Writes a formula from a plain-English description of your columns and the result you want.
• Explains an existing formula piece by piece, including what each function and cell reference does.
• Suggests test rows and awkward cases (blanks, text in number columns, duplicates) to check the result.

Tools to look at

• AI built into spreadsheets, such as Copilot in Excel or Gemini in Google Sheets, depending on your plan
• General assistants (ChatGPT, Claude, Gemini)
• Microsoft’s and Google’s own function references, to check what a function does

Named tools are examples, not endorsements. We have no paid relationships with them at the moment; see our disclosure.

What you need first

• Column names and a few rows of made-up or anonymised sample data, not real customer or staff records.
• Which program you use. Excel and Google Sheets share many functions but not all of them, so say which one you need.
• A test you never skip: check the formula on rows where you already know the answer. A formula can look right and still be subtly wrong.

How to measure ROI

• Time spent stuck on a formula, compared with before.
• Errors caught by your test rows before the sheet was used.
• Whether you could explain the formula to a colleague afterwards.

Run the numbers in the ROI calculator →

What the evidence says

No statistics cited. Microsoft and Google both publish function references for their spreadsheets; use them to check any function the AI suggests.

I use [Excel / Google Sheets]. Help me with a formula.

MY COLUMNS AND SAMPLE ROWS (made-up data):
"""[paste headers and 5 to 10 rows]"""

WHAT I WANT: [describe in plain English, e.g. "total of column D where column B is 'Paid' and the date in A is this month"]
OR EXPLAIN THIS FORMULA: [paste the formula]

1. Give the formula, and say which cell it goes in.
2. Explain it piece by piece in plain British English.
3. Work out by hand what it should return for my sample rows, so I can compare.
4. List awkward cases that could break it (blanks, text, duplicates, dates stored as text) and how to handle them.
5. If a function you use isn't available in my program, say so and give an alternative.

Sources

1. Microsoft Support, "Overview of formulas in Excel" Vendor documentation
2. Google Docs Editors Help, "Google Sheets function list" Vendor documentation

Last updated 29 October 2026. Spotted something out of date? Email support@aiforthisjob.com. How we research and check playbooks.