Guide
Excel’s Row Limit: What Happens after Row 1,048,576
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Every Excel worksheet has a fixed grid of 1,048,576 rows by 16,384 columns (the last cell is XFD1048576). The numbers look arbitrary, but they are powers of two: 220 rows and 214 columns. The limit has been the same since Excel 2007 introduced the .xlsx format, and it applies to the 64-bit version too — more memory does not give you more rows.
The Limits at a Glance
| Program | Rows | Columns | Notes |
|---|---|---|---|
| Excel 2007 and later, Microsoft 365 | 1,048,576 | 16,384 | Per worksheet; 32,767 characters per cell |
Excel 97–2003 (.xls) | 65,536 | 256 | Still applies when saving as .xls |
| Google Sheets | 10 million cells, rising to 20 million from September 2026, or 18,278 columns, per spreadsheet | Rows × columns, across all tabs | |
| LibreOffice Calc | 1,048,576 | — | Same row ceiling as Excel |
| Excel Data Model (Power Pivot) | Not bound by the grid | Limited by memory and file size | |
What Happens When a CSV Has More Rows
When you open a CSV with more than 1,048,576 lines, Excel loads rows up to the limit, then stops and shows a message that the file was not loaded completely. Everything after the last row is not in the workbook at all. There is no second sheet and no hidden overflow.
The dangerous moment is saving. If you press Save while the CSV is open, Excel writes back only what it loaded, and the original file loses every row past the limit. If you have seen that warning, close the file without saving, or use Save As with a new name.
Remember that the header takes a row too, so a sheet holds at most 1,048,575 data rows plus the header. And the row number in the corner of a worksheet is not a row count: if it reads exactly 1,048,576 you are almost certainly looking at a truncated file. How to count the rows in a CSV gives you the real number without opening the file, and explains why a line count and a row count are not the same thing.
Before the Row Limit: The Speed Limit
Many files never reach the row limit and are still painful. Excel analyses every value as it opens a CSV, deciding whether it is a number, a date or text, and applies formatting. A file of 500,000 rows and 40 columns is 20 million cells, and on an ordinary laptop that can mean minutes of waiting and a very slow workbook. Deleting unused columns, or splitting out only the rows you need, helps far more than a faster computer.
That same value-by-value analysis is what silently rewrites your data: ZIP code 02134 loses its zero and a 16-digit reference loses its last digit. If the file has to end up as a workbook, import it rather than open it — how to convert a CSV to Excel without breaking your data.
Ways to Work with Files over the Limit
- Split the file into parts of up to 1,000,000 rows, each with the header. Split a large CSV.
- Filter before opening by splitting on a column such as region or month, so each file is small.
- Use the Data Model via Data › Get Data › From Text/CSV › Load To › Add this data to the Data Model for PivotTables over millions of rows.
- Use a tool built for big data, such as DuckDB or Python, when you need to query the whole file. The guide on opening large CSV files compares the options.
A worksheet is not the only thing with a ceiling. Import screens for CRMs, e-commerce platforms and mailing tools cap uploads by rows, by megabytes or by cells, and each wants a different split — how to split a CSV to fit an import limit collects the published figures, and is there a CSV file size limit? covers the rest, from email attachments to USB drives. If Excel refuses a file that is well under the limit, why a CSV won’t open in Excel goes through the other causes.