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Importing Excel, CSV, and TSV

Updated 2026-06-22

If you've already built your math in Excel or exported it as CSV or TSV, you don't need to retype it. The Formula tab can import an entire file directly into your project's spreadsheet.

Supported file types

| Type | Extension | Brings in | |---|---|---| | Excel | .xlsx | Values, formulas, styling, column widths, row heights, and every worksheet | | Comma-separated | .csv | Values only | | Tab-separated | .tsv | Values only |

Legacy .xls files are not supported. Open the file in Excel and re-save it as .xlsx, then import that.

How to import

  1. Open the Formula tab in your project.
  2. Click Import Excel in the top-right of the spreadsheet.
  3. Pick a .xlsx, .csv, or .tsv file.
  4. If the import area already has data, confirm the replace prompt (see below).

Your file lands starting at column D, leaving the reserved columns A, B, and C untouched.

Multiple worksheets become tabs

When you import a multi-sheet .xlsx workbook, each worksheet becomes its own tab in your spreadsheet. The first worksheet lands on the main tab (where inputs and results connect); the rest become reference tabs created automatically. After import you're returned to the main tab. Empty worksheets are skipped so stray blank sheets don't clutter your project. CSV and TSV files always produce a single sheet.

For how to read across tabs, see Working with multiple sheets / reference data.

Formulas keep working — references shift by 3 columns

Because imported data starts at column D, every column reference in your formulas is shifted three columns to the right on the way in. A formula that read =A1+B1 in Excel becomes =D1+E1 after import. Absolute references ($A$1), ranges (A1:B5), and sheet-prefixed references (Sheet1!A1) are all shifted consistently, and text inside quotes is left alone — so cross-sheet formulas stay internally correct without any manual fixing.

Re-importing preserves your input columns

If you import a second file into a spreadsheet that already holds imported data, Numio asks first:

Replace existing import? Importing will replace the existing content in columns D and to the right (on every imported tab). Columns A and B (your input rows) are preserved.

Confirm to replace the data from column D onward; cancel to keep what you have. A re-import that's smaller than the previous one clears the leftover cells. You can also undo an import with Cmd+Z / Ctrl+Z.

Where to go next