A CSV file already contains tabular data that Excel can open, but CSV and Excel workbook formats are not the same. If you want formulas, multiple worksheets, formatting, charts, or other Excel features, open or import the CSV and then save the result as an .xlsx workbook.
For a simple CSV, open and save it as XLSX
- Open the CSV file in Excel.
- Check that columns, dates, numbers, and special characters were interpreted correctly.
- Choose Save As.
- Select Excel Workbook (*.xlsx).
- Save the new file with a different name if you want to preserve the original CSV.
Use an import when data interpretation matters
For files containing leading zeros, long identification numbers, ambiguous dates, unusual delimiters, or specific text encoding, use Excel’s text/CSV import tools. They provide more control over how incoming columns are interpreted.
Watch for leading zeros
Values such as ZIP codes, product codes, or account identifiers can lose leading zeros if Excel treats them as numbers. Import those columns as text when the zeros are meaningful.
CSV cannot preserve workbook features
A CSV stores plain delimited values. It does not preserve formulas as working formulas in the same way as an Excel workbook, nor does it support multiple sheets, cell formatting, charts, or many other Excel features.
Changing the extension is not conversion
Renaming file.csv to file.xlsx does not convert its internal format. Open/import the data and save it using Excel’s workbook format instead.
Matt Jacobs has been working as an IT consultant for small businesses since receiving his Master’s degree in 2003. While he still does some consulting work, his primary focus now is on creating technology support content for SupportYourTech.com.
His work can be found on many websites and focuses on topics such as Microsoft Office, Apple devices, Android devices, Photoshop, and more.