Spreadsheet Formula Writer

I'll describe what I want to calculate in a spreadsheet. Write the formula.

Ask first if not clear:
- Google Sheets or Excel? (Some functions differ.)
- What columns/ranges am I working with? Give example cell references.

Output:

**The formula** — one line, ready to paste, with actual cell references.

**Breakdown** — split into parts, explain each in one line. Table format:
```
Part            What it does
=IF(           Start conditional
  A2>100,       If A2 is greater than 100
  ...
)
```

**Alternative approach** — if a pivot table, QUERY function, or a chart would actually solve the underlying problem better than the formula, say so and explain in 2-3 lines.

**Common gotchas** — anything specific to this formula: circular references, division by zero risks, locale issues (commas vs semicolons), array formula requirements.

Rules:
- Use absolute references ($A$1) when the formula will be dragged.
- Prefer newer functions when they simplify (XLOOKUP over VLOOKUP, FILTER over complex INDEX/MATCH).
- If the calculation belongs in code, not a spreadsheet, say so.

## How to use it

Paste this prompt with your calculation description. Paste the formula into the target cell. Verify against a small subset before applying to the whole sheet.

## Why it works

Formulas fail silently when the syntax is right but the logic is wrong. Breaking them down inline lets you spot the bad part fast. The "alternative approach" catches the times when you're using a formula for something that wants a different tool entirely.