##### error in Excel
The cell is showing a number that does not fit its column, or a date or time that is negative.
What ##### means
Hash marks fill a cell when Excel cannot display the value, and it is the only error here that is not really an error. The number is stored correctly. The cell is just too small to show it, and Excel prefers marks over a cut-off digit that would look like a different number.
The reasons are physical. Either the column width is smaller than the formatted number, or the value cannot exist in the format it was given, which is the case for negative dates and times.
Because the formula is fine, no function will cure it. The fix is in the column width or the cell format, and it takes seconds once you know.
A quick diagnosis: click the cell and look at the formula bar. If you see a sensible number there, the column is too narrow. If the number is negative and the cell is formatted as a date or a time, the format is the culprit. Both situations look identical on screen and take different fixes, which is why it pays to check before reaching for the column border.
Numbers formatted as Currency or with many decimal places are wider than the same number in General, so a column that was wide enough yesterday can start showing hash marks after a format change. Text never produces this display: a long label simply spills into the next empty cell or is cut off at the neighbor.
Causes of ##### and how to fix each
1. The column is too narrow for the number
Excel never cuts a number short, because a truncated number would look like a different one. If the formatted value is wider than the column, it shows hash marks instead. The value in the cell is fine, and the formula bar shows it in full.
| A | B | C | |
|---|---|---|---|
| 1 | Units | Price | Revenue |
| 2 | 1234568 | 1000 | ##### |
Fix. Double-click the border on the right edge of the column header to AutoFit it, or drag the border wider. Shrinking the number format (fewer decimals, or Thousands) also helps. The keyboard route is Alt, H, O, I, which is AutoFit Column Width.
2. A negative date or time
Excel stores dates as serial numbers counting from January 1, 1900, so a date before 1900 does not exist, and negative times are not allowed in the 1900 date system either. When a subtraction produces a negative number in a cell formatted as a date or time, Excel shows hash marks.
| A | B | C | |
|---|---|---|---|
| 1 | Start | End | |
| 2 | 3/1/2026 | 3/5/2026 | ##### |
| 3 |
Fix. Reverse the subtraction so the later date comes first, or change the cell format from a date back to General or Number so the result shows as -4. Use ABS if only the size of the gap matters.
Trapping ##### in a formula
##### is a display problem, not a formula error, so IFERROR does nothing for it. The value underneath is intact and other formulas can still use it. Widening the column or changing the format is the whole fix.
If a report must stay narrow, apply a shorter number format such as Thousands, or wrap the text, so the number fits without hash marks.
##### on Excel job tests
If a prompt says to make the values readable and a total shows hash marks, widen the column with AutoFit. Changing the number to something smaller would be wrong, because the value must stay as calculated.
On date tasks, a subtraction in the wrong order gives hash marks. Check the order of the two dates before assuming the formula is broken.
Related guides
##### questions
- Why does my Excel cell show ##### instead of a number?
- The column is too narrow to show the formatted value. Double-click the right edge of the column header to AutoFit it.
- Is the data lost when a cell shows #####?
- No. Click the cell and the formula bar shows the real value. Only the display is affected.
- Why do I get ##### for a date?
- Either the column is too narrow for the date format, or the date is negative, for example after subtracting a later date from an earlier one in a cell formatted as a date.
- What is the AutoFit shortcut?
- On Windows, Alt then H, O, I autofits the selected columns. Double-clicking the right border of the column header does the same.
Practice working with errors
The free 5-item sampler uses the same kind of formulas in a working grid, and it shows you the error value when a formula goes wrong.
Try a 5-item Excel test sample