Excel formula generator: describe it in words, get a working formula
You know what the spreadsheet should do, but not whether it needs XLOOKUP, SUMIFS or a nested IF. Describe your columns and the result you want, and your todo.is agent writes the formula, explains each part, tests it on a copy of your data and sends back a workbook with the formula already in place.
The prompt
- Write an Excel formula that [WHAT THE FORMULA SHOULD DO]. My data: [DESCRIBE YOUR COLUMNS] (or use the attached file). Put the result in [TARGET CELL OR COLUMN]. I use [EXCEL VERSION]. Give me the formula ready to paste, explain each part in plain words, and handle blanks and errors so it doesn't show #N/A or #DIV/0!. Test it on my data and send back the workbook (.xlsx) with the formula filled down, plus one simpler alternative if my version doesn't support it.
What to change
- [WHAT THE FORMULA SHOULD DO]: Plain words, e.g. "looks up each order's customer region from the Customers sheet" or "adds sales per rep for the month in B1".
- [DESCRIBE YOUR COLUMNS]: Sheet names, columns and what's in them, e.g. "Orders: A order ID, B customer ID, C amount, D date". Or attach the .xlsx.
- [TARGET CELL OR COLUMN]: E.g. "column E of the Orders sheet" or "cell H2".
- [EXCEL VERSION]: E.g. "Microsoft 365", "Excel 2019", "Excel for Mac 2016". Older versions don't have XLOOKUP or FILTER.
Example result
- Formula for Orders!E2
- Goal: show each order's customer region from the Customers sheet, and sum sales per region.
- Paste in E2 and fill down:
- =IFERROR(XLOOKUP(B2, Customers!A:A, Customers!D:D), "Unknown")
- How it works
- • XLOOKUP(B2, ...) looks for this row's customer ID (B2)
- • Customers!A:A is where it searches: the ID column on the Customers sheet
- • Customers!D:D is what it returns: the region from the same row
- • IFERROR(..., "Unknown") shows "Unknown" instead of #N/A when an ID isn't found
- Sales per region (summary table)
- In the Summary sheet, with region names in A2:A6:
- =SUMIFS(Orders!C:C, Orders!E:E, A2, Orders!D:D, ">="&DATE(2026,9,1), Orders!D:D, "<"&DATE(2026,10,1))
- This adds the amount (column C) for orders in that region during September 2026.
- For Excel 2016 or 2019 (no XLOOKUP)
- =IFERROR(INDEX(Customers!D:D, MATCH(B2, Customers!A:A, 0)), "Unknown")
- The 0 in MATCH means exact match. Leave it out and you get wrong regions.
- Test results
- • 1,240 orders checked, 1,236 matched a customer
- • 4 rows show "Unknown": IDs C-1088, C-1102, C-1140 and C-1201 are missing from Customers
- • Two IDs had a trailing space; wrapping B2 in TRIM() fixed them
- In the file
- • orders_with_region.xlsx: your data with column E filled, a Summary sheet with the SUMIFS table, and a note in E1 with the formula explained
How to do it with todo.is
- Copy the prompt and describe your goal and your columns in the brackets.
- Attach the spreadsheet (or a copy with fake numbers) on the Today screen in todo.is, or send it to your agent on WhatsApp or Telegram.
- Your agent writes the formula, checks it against your rows and explains it in plain words.
- Download the .xlsx with the formula in place, or copy the formula into your own file.
- Reply with what's still off ("ignore cancelled orders too") and it adjusts the formula.
Tips for a better result
- Say which Excel version you use. XLOOKUP, FILTER, UNIQUE and LET need Microsoft 365 or Excel 2021 and later.
- Give one example row and the answer you expect, e.g. "for C-1001 it should say North". It catches misunderstandings fast.
- Ask for an Excel Table version with structured references (=[@Amount]) if your data keeps growing.
- Lookup failures are often hidden spaces or numbers stored as text. Ask your agent to check for both.
- Your agent remembers your sheet layout, so the next formula request can be one sentence.
Excel formula generator: FAQ
- What is the best Excel formula for looking up a value? In Microsoft 365 and Excel 2021, XLOOKUP is simplest and handles missing values with its own fallback argument. In older versions, INDEX with MATCH(…, 0) does the same job and is more flexible than VLOOKUP.
- Why does my Excel formula return #N/A? A lookup returns #N/A when it can't find the value, usually because of extra spaces, text versus number mismatches or a missing exact-match setting. Wrap it in IFERROR for display, but fix the cause with TRIM or VALUE.
- Can it write array formulas or dynamic arrays? Yes. It can use FILTER, SORT, UNIQUE and SEQUENCE for Microsoft 365, or the older Ctrl+Shift+Enter style for earlier versions if you tell it which you have.
- Is my spreadsheet kept private? Files you attach stay in your own agent workspace and only your agent uses them. You can also send a copy with fake values if the data is sensitive.
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