Convert text to number in Excel

If the green triangle is present but Convert to Number does not appear, use one of these supported methods:

1. Try the error indicator path first:
   • Select the cells.
   • Select the error indicator in the top-left of the selected cell, or press Alt+Shift+F10.
   • Select Convert to Number.
2. If the alert button is missing, enable error checking:
   • Go to File > Options.
   • Select Formulas.
   • Under Error Checking, turn on Enable background error checking.
3. If conversion still is not offered, use a formula:
   • Insert a new column next to the text values.
   • In the first row of the new column, enter =VALUE(cell) using the matching source cell reference.
   • Fill the formula down.
   • Copy the results.
   • Paste back over the original column using Paste Special > Values.
4. If the exported data contains extra spaces or nonprintable characters, clean it first:
   • Use TRIM to remove extra spaces.
   • Use CLEAN to remove nonprintable characters.
   • Then convert again with VALUE or Convert to Number.
5. Another workaround for imported values:
   • Select the column.
   • Set the number format to General.
   • On the Data tab, select Text to Columns.
   • Choose Delimited, then select Finish.

Expected result after successful conversion: the green triangle is removed, and the values are treated as numbers for calculation and analysis.

References:

• Convert numbers stored as text to numbers in Excel
• Fix text-formatted numbers by applying a number format
• Conversion numbers in text format to number format. - Microsoft Q&A