code: public static function pixelsToCellDimension($pValue, \PhpOffice\PhpSpreadsheet\Style\Font $pDefaultFont)
      {
          // Font name and size
          $name = $pDefaultFont->getName();
          $size = $pDefaultFont->getSize();
  
          if (isset(Font::$defaultColumnWidths[$name][$size])) {
              // Exact width can be determined
              $colWidth = $pValue * Font::$defaultColumnWidths[$name][$size]['width'] / Font::$defaultColumnWidths[$name][$size]['px'];
          } else {
              // We don't have data for this particular font and size, use approximation by
              // extrapolating from Calibri 11
              $colWidth = $pValue * 11 * Font::$defaultColumnWidths['Calibri'][11]['width'] / Font::$defaultColumnWidths['Calibri'][11]['px'] / $size;
          }
  
          return $colWidth;
      }
docs: Convert pixels to column width. Exact algorithm not known.
  By inspection of a real Excel file using Calibri 11, one finds 1000px ~ 142.85546875
  This gives a conversion factor of 7. Also, we assume that pixels and font size are proportional.
  
  @param int $pValue Value in pixels
  @param \PhpOffice\PhpSpreadsheet\Style\Font $pDefaultFont Default font of the workbook
  
  @return int Value in cell dimension