Alt+H+O+I on a Mac: auto-fit column width

Option, then H O I, auto-fits the column width in Excel for Mac with RibbonKeys, the same sequence as Alt+H+O+I on Windows. H opens the Home tab, O opens Format, and I is Auto-fit Column Width.

The same Format menu has Auto-fit Row Height on A, so H O A fits the row. Column Width is H O W, and Row Height is H O H. The Excel 2003 menu key O C A is Format, Column, Auto-fit Selection, which is a different command from H O I.

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Needs macOS 13 or later and Excel for Mac.

Windows Excel shortcuts on a Mac · RibbonKeys compared · Every shortcut · RibbonKeys