Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Shared/Xls.php
public static function sizeCol($sheet, $col = 'A')
    {
        // default font of the workbook
        $font = $sheet->getParent()->getDefaultStyle()->getFont();

        $columnDimensions = $sheet->getColumnDimensions();

        // first find the true column width in pixels (uncollapsed and unhidden)
        if (isset($columnDimensions[$col]) and $columnDimensions[$col]->getWidth() != -1) {
            // then we have column dimension with explicit width
            $columnDimension = $columnDimensions[$col];
            $width = $columnDimension->getWidth();
            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
        } elseif ($sheet->getDefaultColumnDimension()->getWidth() != -1) {
            // then we have default column dimension with explicit width
            $defaultColumnDimension = $sheet->getDefaultColumnDimension();
            $width = $defaultColumnDimension->getWidth();
            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
        } else {
            // we don't even have any default column dimension. Width depends on default font
            $pixelWidth = Font::getDefaultColumnWidthByFont($font, true);
        }

        // now find the effective column width in pixels
        if (isset($columnDimensions[$col]) and !$columnDimensions[$col]->getVisible()) {
            $effectivePixelWidth = 0;
        } else {
            $effectivePixelWidth = $pixelWidth;
        }

        return $effectivePixelWidth;
    }
public static function sizeCol($sheet, $col = 'A')
    {
        // default font of the workbook
        $font = $sheet->getParent()->getDefaultStyle()->getFont();

        $columnDimensions = $sheet->getColumnDimensions();

        // first find the true column width in pixels (uncollapsed and unhidden)
        if (isset($columnDimensions[$col]) and $columnDimensions[$col]->getWidth() != -1) {
            // then we have column dimension with explicit width
            $columnDimension = $columnDimensions[$col];
            $width = $columnDimension->getWidth();
            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
        } elseif ($sheet->getDefaultColumnDimension()->getWidth() != -1) {
            // then we have default column dimension with explicit width
            $defaultColumnDimension = $sheet->getDefaultColumnDimension();
            $width = $defaultColumnDimension->getWidth();
            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
        } else {
            // we don't even have any default column dimension. Width depends on default font
            $pixelWidth = Font::getDefaultColumnWidthByFont($font, true);
        }

        // now find the effective column width in pixels
        if (isset($columnDimensions[$col]) and !$columnDimensions[$col]->getVisible()) {
            $effectivePixelWidth = 0;
        } else {
            $effectivePixelWidth = $pixelWidth;
        }

        return $effectivePixelWidth;
    }
Get the width of a column in pixels. We use the relationship y = ceil(7x) where
x is the width in intrinsic Excel units (measuring width in number of normal characters)
This holds for Arial 10.

@param Worksheet $sheet The sheet
@param string $col The column

@return int The width in pixels