The row will effectively be hidden. It can still be accessed and even have values in it that can be used in formulas.
When you decrease it to zero it is effectively hidden. A row can actually be hidden, without changing its width.
12.75 is the standard height.
When you reduce the row height in excel the row is hidden
In Excel 2007 it is 1,048,576 rows. If you really wanted to ask what is the height of a row, then the answer is 15.
hidden
By selecting an empty row and pressing Ctrl + 'Down arrow key', the selected cell will be the next item down the column. The row height in Excel 2010 is 1048576 cells.
Default row height in Excel 2007 is 15, if you leave the default font and font size alone. The default row height depends on the default font. For example, if you change the font and font size in Excel Options to Arial 10, the default row height will become the more familar 12.75 from Excel 2003.
Row height can adjust automatically when things are done, like text made larger.
In Microsoft Excel, you can auto adjust row height by double clicking the row separation line between two rows.
You set it to zero.
row height = 15 column width = 8.43
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It is considered to have 0 height, at least temporarily. However, there is no need to decrease the row height to 0 for a hidden row. If you do, when the row is unhidden it will unhide to the default height (generally 15). For example, you could hide a row of height 50, and when you unhide it it will still be of height 50, not the default.