Code to Set Width of Cell in Excel using C#. A detailed article is available here for further description: https://kb.aspose.com/cells/net/how-to-set-width-of-cell-in-excel-using-csharp/

How to Set Width of Cell in Excel using C#.cs

using Aspose.Cells;

namespace SetWidthOfCellInExcelUsingCSharp
{
    class Program
    {
        static void Main(string[] args) // Main function to set width of cell in CSharp
        {
            // Instantiate the license to remove trial version watermark in the output Excel file
            Aspose.Cells.License licForCells= new Aspose.Cells.License();
            licForCells.SetLicense("Aspose.Svg.lic");
  
            // Create a workbook class object to set column width
            Workbook wb = new Workbook();

            // Access the first worksheet from the default collection of worksheets
            Worksheet ws = wb.Worksheets[0];

            // Set the column width to 20.0
            ws.Cells.SetColumnWidth(1, 20.0);

            // Saving the Excel file having specified column width
            wb.Save("output.xlsx");

            System.Console.WriteLine("Done");
        }       
    }
}