diff --git a/composer.json b/composer.json
index 0c98ee6..662aa6d 100644
--- a/composer.json
+++ b/composer.json
@@ -20,6 +20,7 @@
   "require": {
     "php": ">=7.1",
     "ext-dom": "*",
+    "ext-pdo": "*",
     "contao-bootstrap/core": "^2.0",
     "contao-community-alliance/meta-palettes": "^2.0 || ^1.11",
     "contao/core-bundle": "^4.4",
diff --git a/src/Definition/Column.php b/src/Definition/Column.php
index daa9698..230d7cc 100644
--- a/src/Definition/Column.php
+++ b/src/Definition/Column.php
@@ -88,6 +88,20 @@ public function width(int $width): self
         return $this;
     }
 
+    /**
+     * Force variable width of column.
+     *
+     * @return Column
+     *
+     * @see https://getbootstrap.com/docs/4.3/layout/grid/#variable-width-content
+     */
+    public function variableWidth(): self
+    {
+        $this->width = 'auto';
+
+        return $this;
+    }
+
     /**
      * Set the flex order.
      *
@@ -168,7 +182,9 @@ public function build(array $classes, string $size = ''): array
     {
         $sizeSuffix = $size ? '-' . $size : $size;
 
-        if ($this->width === null || $this->width > 0) {
+        if ($this->width === 'auto') {
+            $classes[] = 'col' . $sizeSuffix . '-auto';
+        } elseif ($this->width === null || $this->width > 0) {
             $widthSuffix = ($this->width > 0) ? '-' . $this->width : '';
             $classes[]   = 'col' . $sizeSuffix . $widthSuffix;
         } elseif ($size) {
diff --git a/src/GridBuilder.php b/src/GridBuilder.php
index 51e2746..f2f600c 100644
--- a/src/GridBuilder.php
+++ b/src/GridBuilder.php
@@ -152,17 +152,8 @@ private function buildSize(string $size, array $definition): void
     private function buildColumn(array $definition): Column
     {
         $column = new Column();
-        if ($definition['width']) {
-            switch ($definition['width']) {
-                case 'auto':
-                    break;
-                case 'null':
-                    $column->width(0);
-                    break;
-                default:
-                    $column->width((int) $definition['width']);
-            }
-        }
+
+        $this->buildColumnWidth($definition, $column);
 
         if ($definition['order']) {
             $column->order((int) $definition['order']);
@@ -219,4 +210,31 @@ private function parseOffset($offset)
 
         return $offset;
     }
+
+    /**
+     * Build the column width.
+     *
+     * @param array  $definition The grid column definition.
+     * @param Column $column     The column.
+     *
+     * @return void
+     */
+    private function buildColumnWidth(array $definition, Column $column): void
+    {
+        if ($definition['width']) {
+            switch ($definition['width']) {
+                case 'variable':
+                    $column->variableWidth();
+                    break;
+                case 'auto':
+                case 'equal':
+                    break;
+                case 'null':
+                    $column->width(0);
+                    break;
+                default:
+                    $column->width((int) $definition['width']);
+            }
+        }
+    }
 }
diff --git a/src/Listener/Dca/GridListener.php b/src/Listener/Dca/GridListener.php
index 2d5317a..a949a50 100644
--- a/src/Listener/Dca/GridListener.php
+++ b/src/Listener/Dca/GridListener.php
@@ -108,7 +108,7 @@ public function generateLabel(array $row): string
     public function getWidths(): array
     {
         $columns = $this->getColumns();
-        $values  = ['auto', 'null'];
+        $values  = ['equal', 'variable', 'null'];
         $values  = array_merge($values, range(1, $columns));
 
         return array_combine($values, $values);
diff --git a/src/Migration/MigrateAutoGridWidths.php b/src/Migration/MigrateAutoGridWidths.php
new file mode 100644
index 0000000..6cdaf21
--- /dev/null
+++ b/src/Migration/MigrateAutoGridWidths.php
@@ -0,0 +1,109 @@
+<?php
+
+/**
+ * Contao Bootstrap grid.
+ *
+ * @package    contao-bootstrap
+ * @subpackage Grid
+ * @author     David Molineus <david.molineus@netzmacht.de>
+ * @copyright  2017-2019 netzmacht David Molineus. All rights reserved.
+ * @license    https://github.com/contao-bootstrap/grid/blob/master/LICENSE LGPL 3.0-or-later
+ * @filesource
+ */
+
+declare(strict_types=1);
+
+namespace ContaoBootstrap\Grid\Migration;
+
+use Contao\StringUtil;
+use Doctrine\DBAL\Connection;
+use PDO;
+use function array_map;
+use function serialize;
+use function time;
+
+/**
+ * Migrate the auto grid widths to equal.
+ */
+final class MigrateAutoGridWidths
+{
+    private const SIZES = ['xs', 'sm', 'md', 'lg', 'xl'];
+
+    /**
+     * Database connection.
+     *
+     * @var Connection
+     */
+    private $connection;
+
+    /**
+     * MigrateAutoGridWidths constructor.
+     *
+     * @param Connection $connection Database connection.
+     */
+    public function __construct(Connection $connection)
+    {
+        $this->connection = $connection;
+    }
+
+    /**
+     * Invoke the migration script.
+     *
+     * @return void
+     */
+    public function __invoke(): void
+    {
+        $statement = $this->connection->executeQuery('SELECT * FROM tl_bs_grid');
+
+        while ($row = $statement->fetch(PDO::FETCH_ASSOC)) {
+            $this->migrateRow($row);
+        }
+    }
+
+    /**
+     * Migrate a grid definition row.
+     *
+     * @param array $row The grid definition row.
+     *
+     * @return void
+     */
+    private function migrateRow(array $row): void
+    {
+        $data = ['tstamp' => time()];
+
+        foreach (self::SIZES as $size) {
+            $size       .= 'Size';
+            $data[$size] = $this->migrateSize($row[$size]);
+        }
+
+        $this->connection->update('tl_bs_grid', $data, ['id' => $row['id']]);
+    }
+
+    /**
+     * Migrate a grid size.
+     *
+     * @param string|null $size The grid size definition.
+     *
+     * @return string|null
+     */
+    private function migrateSize(?string $size): ?string
+    {
+        if ($size === null) {
+            return null;
+        }
+
+
+        $columns = array_map(
+            function (array $column) {
+                if ($column['width'] === 'auto') {
+                    $column['width'] = 'equal';
+                }
+
+                return $column;
+            },
+            StringUtil::deserialize($size, true)
+        );
+
+        return serialize($columns);
+    }
+}
diff --git a/src/Resources/config/services.yml b/src/Resources/config/services.yml
index 207301d..b2b38dd 100644
--- a/src/Resources/config/services.yml
+++ b/src/Resources/config/services.yml
@@ -53,3 +53,8 @@ services:
   contao_bootstrap.grid.response_tagger:
     alias: netzmacht.contao_toolkit.response_tagger
     public: true
+
+  ContaoBootstrap\Grid\Migration\MigrateAutoGridWidths:
+    public: true
+    arguments:
+      - '@database_connection'
diff --git a/src/Resources/contao/config/runonce.php b/src/Resources/contao/config/runonce.php
new file mode 100644
index 0000000..caae191
--- /dev/null
+++ b/src/Resources/contao/config/runonce.php
@@ -0,0 +1,18 @@
+<?php
+
+/**
+ * Contao Bootstrap grid.
+ *
+ * @package    contao-bootstrap
+ * @subpackage Grid
+ * @author     David Molineus <david.molineus@netzmacht.de>
+ * @copyright  2017-2019 netzmacht David Molineus. All rights reserved.
+ * @license    https://github.com/contao-bootstrap/grid/blob/master/LICENSE LGPL 3.0-or-later
+ * @filesource
+ */
+
+use ContaoBootstrap\Grid\Migration\MigrateAutoGridWidths;
+
+(function () {
+    \Contao\System::getContainer()->get(MigrateAutoGridWidths::class)();
+})();