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Excel guide · 3 min read

##### in Excel: why it happens and how to fix it

Quick answer##### means the value does not fit in the cell. Usually the column is just too narrow for the number or date: double-click the right edge of the column header to widen it. If widening does not help, the cell holds a negative date or time, which Excel cannot display. Fix the formula so the result is positive, or show it as a number of days instead of a date.

Sample data

Every result on this page was calculated from this sheet by the same spreadsheet engine the Cellwise app uses.

ABC
1TaskDueDone
2Proposal2026-11-062026-11-04
3Budget2026-11-132026-11-18
4Launch2026-11-272026-11-20

Cause 1: the column is too narrow

Excel never cuts a number or date in half, because a partial number could be read as a different value. When it does not fit, Excel fills the cell with hashes instead. Text is different: it spills into the next empty cell or gets cut off, but never turns into #####.

This is the cause most of the time, especially after you apply a currency or long date format, or paste values into a narrow column.

  1. Move the pointer to the right edge of the column header until it becomes a double arrow.
  2. Double-click to AutoFit the column to its widest entry.
  3. For many columns: select them, then Home > Format > AutoFit Column Width.
  4. Prefer a fixed width? Shrink the font or use a shorter format (for example 11/6/26 instead of Friday, November 6, 2026).

Cause 2: a negative date or time

Dates are counted in days since January 1, 1900, so there is no date before day 1. If a formula subtracts the later date from the earlier one and the cell is formatted as a date, Excel cannot show the negative result and displays ##### however wide the column is.

Here the Budget task was due on November 13 and done on November 18. Due minus Done is -5 days, which as a date shows #####. As a plain number it is simply -5.

=B3-C3

Result: -5

-5: done 5 days after the due date. Formatted as a date, this cell would show #####.

Fix: show days, not a date, and make the sign mean something

Set the result cell to General or Number (Home > Number Format > General) so it shows a count of days. Then make the meaning explicit instead of leaving a confusing negative number.

=IF(C3>B3,"Late by "&(C3-B3)&" days","On time")

Result: Late by 5 days

Budget finished 5 days after its due date, so the label reads Late by 5 days.

If you only need the size of the gap

When the order of the dates does not matter, ABS removes the sign so the result is always positive and never shows #####.

=ABS(B3-C3)

Result: 5

5 days between the two dates, whichever comes first.

Times that cross midnight

A night shift from 22:00 to 6:00 gives a negative result with =C2-B2, so a time-formatted cell shows #####. Add one day when the end is earlier than the start: =MOD(C2-B2,1). MOD wraps the negative fraction of a day back into a positive time (8:00 here). Multiply by 24 for decimal hours: =MOD(C2-B2,1)*24 returns 8.

Common mistakes

Widening the column forever

If the hashes stay at any width, the value is a negative date or time. Change the formula, not the column.

Using the 1904 date system to hide negative times

File > Options > Advanced > Use 1904 date system does allow negative times, but it shifts every existing date in the workbook by four years. Use MOD or IF instead.

Treating ##### as an error in IFERROR

##### is a display problem, not an error value. IFERROR and ISERROR do not see it, and the cell still holds a valid number.

FAQ

Why does my Excel cell show #####?

Either the column is too narrow for the number or date, or the value is a negative date or time. Double-click the column edge first; if the hashes stay, check the formula.

How do I get rid of ##### in Excel?

Widen the column (double-click the right edge of the header). If that does not work, change the cell format to General to see the real negative number, then fix the formula.

Why does Excel show ##### for a negative time?

Excel's default 1900 date system cannot display times or dates below zero. Use =MOD(end-start,1) for shifts that cross midnight.

Functions used

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