How to use AI in Excel and Google Sheets

Which AI to use for this

Step by step

1. 1

   Describe your columns exactly

   This is the whole job. The AI cannot see your spreadsheet, so it guesses your layout unless you tell it — and a formula built on a guessed layout returns a wrong number rather than an error, which is worse.

   Paste thisCopy

   I'm in Excel. My sheet has:
   - Column A: property address (text)
   - Column B: monthly rent (number)
   - Column C: date rent received (date, some cells blank)
   - Column D: date rent was due (date)
   Rows 2 to 180 have data. Row 1 is headings.
   
   I want a formula in column E that says LATE if the rent came in more than 3 days after it was due, PAID if it was on time, and NOT YET if column C is blank.
   
   Give me the formula only, then explain it in one sentence.

   Say Excel or Google Sheets — they are not the same and some functions only exist in one. Say which row your data starts on. Say when a column can be blank.

2. 2

   Paste it into ONE cell first

   Not the whole column. One cell, on a row where you already know the right answer. If it agrees with you, you have a formula. If it does not, you have saved yourself an afternoon.

3. 3

   Test it on the awkward rows

   Pick three rows deliberately: an easy one, an empty one, and the weirdest one in the sheet. Most formula bugs live in blanks, zeros and dates, not in the ordinary rows.

4. 4

   Get the error explained instead of guessing

   If Excel shows you #VALUE! or #REF! or a wall of green triangles, paste the formula and the error back in. Explaining errors is the thing these models are best at.

   Paste thisCopy

   This formula is giving me #VALUE! in some rows but not others:
   
   [paste your formula here]
   
   Column C has dates but some cells are blank and a few contain the text "cash". What's going wrong, and what should the formula be instead?

   Tell it what is actually in the awkward cells. "Some cells contain the word cash" is the sentence that solves it.

5. 5

   Have any formula explained back to you

   Inherited a spreadsheet nobody understands? This is the single most useful thing on this page, and it works on formulas nested six deep.

   Paste thisCopy

   Explain what this formula does, in plain English, as if I've never used a spreadsheet:
   
   [paste the formula]
   
   Then tell me the one thing most likely to break it.

What a good answer looks like

Not a made-up example. This is one of the spreadsheets & excel tasks from our published suite, and what GPT-5.6 Luna actually wrote when it sat it — printed exactly as it was stored, with the mark the judges gave it.

One thing to know before you read it: it was marked against the rules that task sets, which are not the rules on this page. A test suite has to stay identical for every model that sits it, so it cannot adopt the tighter prompt above. Read the answer for the shape of a good one — facts early, constraint respected, a clear next step — not as a template to copy.

```excel
=SUMIFS(B:B,A:A,">="&(EOMONTH(TODAY(),-2)+1),A:A,"<"&(EOMONTH(TODAY(),-1)+1))
```

This sums order values whose dates fall from the first day through the end of the last completed calendar month.

The full answer, all twelve tasks and every judge’s score →

Common mistakes

• Uploading the whole spreadsheet and hoping.

  Describe the columns instead. It is faster, it works on every AI including the free ones, and it does not hand your tenants' or customers' data to a company you have not read the policy of.

• Trusting a formula because it ran without an error.

  A wrong formula usually runs perfectly. Check it against a row where you already know the answer — every time, not just the first time.

• Asking for "a formula to sort this out".

  Say what the answer should be, in words, for one specific row. "Row 7 should say LATE because it came in 5 days after it was due."

• Asking it to add up your numbers.

  Get it to write the formula and let the spreadsheet do the arithmetic. These models are far better at writing a SUM than at being one.

Questions people ask