Microsoft Excel might show ##### in cells when a column isn’t wide enough to show all of the cell contents. Formulas that return dates and times as negative values can also show as #####.
To make a column wider to show cell contents in full, double-click the right edge of the column header, or drag it to the width you want.
You can also try the following:
To make the cell contents smaller, click Home > next to Alignment, and then check the Shrink to fit box in the Format Cells dialog box.
If numbers have too many decimal places, click Home > Decrease Decimal.
If dates are too long, click Home > arrow next to Number Format, and pick Short Date.
Correct negative dates or times
When Excel shows ##### because the cell has a negative date or time value, make sure that you:
Verify dates and times are positive values when you’re using the 1900 date system.
Use a formula to subtract dates or Add or subtract time correctly to avoid negative date or time value results.
Change negative formula results that are formatted as dates or times to a different number format.