When to use
- You need a real spreadsheet — a P&L, a commission calculator, a budget, a data cleanup — not a table of numbers pasted into chat.
- You have an existing workbook and want a column, formula, or sheet added that matches its existing conventions and formatting.
- You want a chart or conditional formatting (like highlighting rows below target) driven by an actual rule, not manually colored cells that go stale the moment the data changes.
- You have messy tabular data (CSV, malformed export) that needs restructuring into a clean, usable file.
Do not use it for Word documents, PDFs, or slide decks — that's the DOCX, PDF, or PPTX skill.
What it does
- Builds new workbooks using real formulas (
=SUM(...),=IF(...), and similar) instead of hardcoded totals, so the sheet recalculates correctly if the underlying numbers change. - Edits existing files by finding their designated input cells and matching conventions exactly — it does not silently redesign a sheet's layout or touch formulas it wasn't asked to change.
- Adds charts and conditional formatting as native Excel objects driven by rules, not one-time manual coloring.
- Recalculates every formula before finishing and reports any cell that errors out, rather than shipping a workbook that reads as blank or broken until the user opens it and recalculates manually.
- Documents assumptions and hardcoded inputs — a cell comment or adjacent note explaining where a number came from, instead of a silent, unexplained figure.
How to use
- Describe the deliverable and share the source data: "Take this CSV of sales, build a P&L by region with a chart, highlight regions under $50k in red."
- If you're editing an existing workbook, share it — Claude matches its existing tab names, headers, and formatting instead of restructuring it.
- State the exact rule for any calculation (commission tiers, growth rate, thresholds) — the skill follows the spec you give rather than guessing a "close enough" formula.
- Open the exported file in Excel or Numbers and spot-check a few cells — a clean recalculation proves the formulas evaluate, not that the underlying logic matches what you actually meant.
Best for
Business owners and teams who need a real, formula-driven spreadsheet — P&Ls, budgets, commission calculators, cleaned-up data — without building it cell by cell themselves.