Range.ColumnWidth (Excel)

Returns or sets the width of all columns in the specified range. Read/write Double.

One unit of column width is equal to the width of one character in the Normal style. For proportional fonts, the width of the character 0 (zero) is used. Use the AutoFit method to set column widths based on the contents of cells. Use the Width property to return the width of a column in points. If all columns in the range have the same width, the ColumnWidth property returns the width. If columns in the range have different widths, this property returns null.

ActiveCell.ColumnWidth = 50