RowlodeLong numbers in a CSV turn into 1.23E+15 in Excel
Excel keeps numbers to 15 significant digits. A 16-digit ID such as 4111111111111111 becomes 4.11111E+15, and if you widen the column you see 4111111111111110 – the last digit is gone for good once you save.
Updated 2026-10-26 · 4 min read
Why it happens
It's not a display problem only: Excel converts the text to a floating-point number with 15 digits of precision. Widening the column or choosing the Number format shows zeros instead of the lost digits. Microsoft documents this limit.
Fix: treat the column as text
- Microsoft 365 / Excel 2024: File › Options › Data › Automatic Data Conversion › untick Keep first 15 digits of long numbers and display in scientific notation if required.
- Any version: Data › From Text/CSV › Transform Data › set the column type to Text.
If you send files to others
Send an .xlsx where the ID column is text. Rowlode's Excel export keeps long digit strings (longer than 15 digits) and values with leading zeros as text, so recipients can double-click without losing digits. It also opens the CSV in a grid without any conversion, so you can check the original values.
Have a big or messy CSV? Rowlode opens CSV files with millions of rows (multi-GB) in your browser, reading them from disk – filter, remove duplicates, sort, fix delimiter and encoding, and export CSV, Excel (split under the row limit), TSV, JSON or NDJSON. Nothing is uploaded. Viewing, filtering and dedupe are free; each export holds the first 10,000 rows until you buy a $12 lifetime license.
Questions and answers
Can I recover the lost digits after saving?
No. Go back to the original CSV and import the column as text.
Does this affect amounts?
Only values with more than 15 significant digits – normal money amounts are fine.
Sources and product names: Microsoft Support: "Keeping leading zeros and large numbers" and "Excel specifications and limits" (15-digit precision). Microsoft Excel and Power Query are trademarks of Microsoft; Google Sheets is a trademark of Google. Rowlode is independent and not affiliated with them.