Understand any Excel formula in plain English
You open a spreadsheet from a colleague and find something like =IFERROR(INDEX(C:C, MATCH(A2, B:B, 0)), ""). It works, but nobody remembers why. This free tool reads the formula for you and explains it step by step: what each function does, what every argument means, which cells it uses, and what could go wrong. It also works the other way: tell it what you want to do and it gives you a ready-to-paste formula.
Everything runs inside your browser. Nothing you type is sent anywhere, so it is safe to paste formulas from work files.
How to explain a formula
- Copy the formula from the Excel or Google Sheets formula bar.
- Paste it into tab ① and press Explain (or Ctrl + Enter).
- Read In plain words first. It is a one-sentence summary of the whole formula.
- Then check Step by step. Nested formulas are explained from the inside out, which is also the order Excel calculates them.
- Look at Watch out. This is where the tool flags common mistakes.
How to get a formula for a task
- Open tab ② and type what you want, for example "split first name" or "days between two dates".
- Pick the closest task card and fill in your own cells and ranges.
- Copy the formula. If you chose an older Excel version at the top, you get a formula that works in that version.
- No matching task? Use Ask an AI the right way. It writes a clear prompt that includes your Excel version and columns, which gets much better answers than a one-line question.
6 formula mistakes this tool catches
- VLOOKUP without FALSE. If the last argument is missing, VLOOKUP uses approximate match and can quietly return the wrong row.
- Numbers in quotes.
A2>"100"compares against text, not the number 100, so the result is usually wrong. - Curly quotes. Formulas copied from websites or Word often contain “smart quotes”, which Excel rejects. The tool replaces them with straight quotes.
- Missing or extra brackets. The tool counts them and shows where the problem is.
- New functions in old Excel. XLOOKUP, FILTER, UNIQUE and TEXTSPLIT show
#NAME?in Excel 2019 and older. The tool warns you and the finder offers older alternatives. - Dividing by a cell that might be empty. You get a tip to wrap the formula in IFERROR so the sheet does not fill up with
#DIV/0!.
Excel vs Google Sheets
Most formulas work the same in both. The differences that trip people up: Google Sheets uses SPLIT instead of TEXTSPLIT; the Sheets version of SORT takes different arguments; and Sheets-only functions like QUERY, ARRAYFORMULA and IMPORTRANGE do not exist in Excel. Choose "Google Sheets" at the top and the tool points these out.
In many countries in Europe and Latin America, Excel uses a semicolon between arguments: =IF(A2>10; "Yes"; "No"). The explainer understands both styles. Tick the semicolon box and every formula the tool gives you uses semicolons and decimal commas.
How this tool was tested
Before it went live, I ran 206 automated checks (188 on the formula logic and 18 on the page), at phone width in a Chromium-based browser. Last full test run: 17 October 2026.
- The formulas were calculated, not only read. Each example formula was run through a spreadsheet calculation engine (HyperFormula) on test data, and the result was compared with the answer I expected.
- The explanations and the finder were checked too: 38 checks on the plain-English explanations and 5 on the task finder.
- Problems found and fixed during testing: six. For example, "Get the last word" returned a blank when a cell ended with a space (real Excel does the same), so the formula now trims the cell first. The fixed formula is
=TRIM(RIGHT(SUBSTITUTE(TRIM(A2), " ", REPT(" ", 100)), 100)), and on the name "George Lim " (with a space at the end) it now returns "Lim".
What the engine could not check: 13 of the example formulas use functions or formats the engine does not have (XLOOKUP, TEXTJOIN, RANK.EQ, UNIQUE, SEQUENCE and the "dddd" weekday format), so those were checked by reading, not by calculating. The tool covers 126 functions, not all of Excel, so some functions are not explained. Always try the result on a few rows. Found a mistake? Tell me on the Contact page.
FAQ
Is it free?
Yes. No sign-up, no limits.
Is my formula sent to a server or an AI?
No. The explanation is made by code running in your own browser. Nothing is uploaded or saved.
Is the explanation always right?
It reads the structure of the formula, so it is reliable about what the formula does. It cannot see your data, though, so it cannot tell you whether a range is the right one. Always test the result on a few rows.
Which functions are supported?
The library describes over 120 of the most used Excel and Google Sheets functions. Other valid functions are still recognised and shown in the breakdown; they just get a shorter description.
It says "#NAME?" will appear. Why?
Usually a spelling mistake in a function name, or a function that your version of Excel does not have. Check the name, or pick an older-version formula in tab ②.