diff --git src/wp-admin/includes/image.php src/wp-admin/includes/image.php
index 9328b1d7d3..eb2c36ce1b 100644
--- src/wp-admin/includes/image.php
+++ src/wp-admin/includes/image.php
@@ -205,7 +205,7 @@ function wp_create_image_subsizes( $file, $image_meta, $attachment_id ) {
  * @since 5.3.0
  * @access private
  *
- * $padam array  $new_sizes     Array defining what sizes to create.
+ * @param array  $new_sizes     Array defining what sizes to create.
  * @param string $file          Full path to the image file.
  * @param array  $image_meta    The attachment meta data array.
  * @param int    $attachment_id Attachment Id to process.
@@ -235,6 +235,7 @@ function _wp_make_subsizes( $new_sizes, $file, $image_meta, $attachment_id ) {
 			'large'        => null,
 			'thumbnail'    => null,
 			'medium_large' => null,
+			'extra_large'  => null,
 		);

 		$new_sizes = array_filter( array_merge( $priority, $new_sizes ) );
diff --git src/wp-admin/includes/schema.php src/wp-admin/includes/schema.php
index 92fd6d6619..394e2405c8 100644
--- src/wp-admin/includes/schema.php
+++ src/wp-admin/includes/schema.php
@@ -546,6 +546,8 @@ function populate_options( array $options = array() ) {

 		// 5.3.0
 		'admin_email_lifespan'            => ( time() + 6 * MONTH_IN_SECONDS ),
+		'extra_large_size_w'              => 2048,
+		'extra_large_size_h'              => 0,
 	);

 	// 3.3
diff --git src/wp-admin/options.php src/wp-admin/options.php
index 4c3a7ef3a7..3ec40bea32 100644
--- src/wp-admin/options.php
+++ src/wp-admin/options.php
@@ -126,6 +126,8 @@ $whitelist_options            = array(
 		'medium_size_h',
 		'large_size_w',
 		'large_size_h',
+		'extra_large_size_w',
+		'extra_large_size_h',
 		'image_default_size',
 		'image_default_align',
 		'image_default_link_type',
diff --git src/wp-includes/class-wp-image-editor-gd.php src/wp-includes/class-wp-image-editor-gd.php
index daec6b3d04..42d1d79fc3 100644
--- src/wp-includes/class-wp-image-editor-gd.php
+++ src/wp-includes/class-wp-image-editor-gd.php
@@ -202,7 +202,8 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 	 * @since 3.5.0
 	 *
 	 * @param array $sizes {
-	 *     An array of image size arrays. Default sizes are 'small', 'medium', 'medium_large', 'large'.
+	 *     An array of image size arrays. Default sizes are 'small', 'medium',
+	 *     'medium_large', 'large', 'extra_large'.
 	 *
 	 *     Either a height or width must be provided.
 	 *     If one of the two is set to null, the resize will
diff --git src/wp-includes/class-wp-image-editor-imagick.php src/wp-includes/class-wp-image-editor-imagick.php
index 1228ca0575..3ec22922e6 100644
--- src/wp-includes/class-wp-image-editor-imagick.php
+++ src/wp-includes/class-wp-image-editor-imagick.php
@@ -415,7 +415,8 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 	 * @since 3.5.0
 	 *
 	 * @param array $sizes {
-	 *     An array of image size arrays. Default sizes are 'thumbnail', 'medium', 'medium_large', 'large'.
+	 *     An array of image size arrays. Default sizes are 'thumbnail', 'medium',
+	 *     'medium_large', 'large', 'extra_large'.
 	 *
 	 *     Either a height or width must be provided.
 	 *     If one of the two is set to null, the resize will
diff --git src/wp-includes/class-wp-xmlrpc-server.php src/wp-includes/class-wp-xmlrpc-server.php
index 260c6f86dc..b3999bec67 100644
--- src/wp-includes/class-wp-xmlrpc-server.php
+++ src/wp-includes/class-wp-xmlrpc-server.php
@@ -611,6 +611,16 @@ class wp_xmlrpc_server extends IXR_Server {
 				'readonly' => false,
 				'option'   => 'large_size_h',
 			),
+			'extra_large_size_w'            => array(
+				'desc'     => __( 'Extra large size image width' ),
+				'readonly' => false,
+				'option'   => 'extra_large_size_w',
+			),
+			'extra_large_size_h'            => array(
+				'desc'     => __( 'Extra large size image height' ),
+				'readonly' => false,
+				'option'   => 'extra_large_size_h',
+			),
 			'default_comment_status'  => array(
 				'desc'     => __( 'Allow people to submit comments on new posts.' ),
 				'readonly' => false,
diff --git src/wp-includes/formatting.php src/wp-includes/formatting.php
index 512d17e67b..02d0e2bfdd 100644
--- src/wp-includes/formatting.php
+++ src/wp-includes/formatting.php
@@ -4506,6 +4506,8 @@ function sanitize_option( $option, $value ) {
 		case 'medium_large_size_h':
 		case 'large_size_w':
 		case 'large_size_h':
+		case 'extra_large_size_w':
+		case 'extra_large_size_h':
 		case 'mailserver_port':
 		case 'comment_max_links':
 		case 'page_on_front':
diff --git src/wp-includes/media.php src/wp-includes/media.php
index 27b1eb8f6e..e22b1cdcc3 100644
--- src/wp-includes/media.php
+++ src/wp-includes/media.php
@@ -33,9 +33,9 @@ function wp_get_additional_image_sizes() {
  * The `$size` parameter accepts either an array or a string. The supported string
  * values are 'thumb' or 'thumbnail' for the given thumbnail size or defaults at
  * 128 width and 96 height in pixels. Also supported for the string value is
- * 'medium', 'medium_large' and 'full'. The 'full' isn't actually supported, but any value other
- * than the supported will result in the content_width size or 500 if that is
- * not set.
+ * 'medium', 'medium_large', 'large', 'extra_large' and 'full'. The 'full' isn't
+ * actually supported, but any value other than the supported will result in the
+ * content_width size or 500 if that is not set.
  *
  * Finally, there is a filter named {@see 'editor_max_image_size'}, that will be
  * called on the calculated array for width and height, respectively. The second
@@ -87,15 +87,15 @@ function image_constrain_size_for_editor( $width, $height, $size = 'medium', $co
 		if ( intval( $content_width ) > 0 ) {
 			$max_width = min( intval( $content_width ), $max_width );
 		}
-	} elseif ( $size === 'large' ) {
+	} elseif ( 'large' === $size || 'extra_large' === $size ) {
 		/*
 		 * We're inserting a large size image into the editor. If it's a really
 		 * big image we'll scale it down to fit reasonably within the editor
 		 * itself, and within the theme's content width if it's known. The user
 		 * can resize it in the editor if they wish.
 		 */
-		$max_width  = intval( get_option( 'large_size_w' ) );
-		$max_height = intval( get_option( 'large_size_h' ) );
+		$max_width  = intval( get_option( "{$size}_size_w" ) );
+		$max_height = intval( get_option( "{$size}_size_h" ) );

 		if ( intval( $content_width ) > 0 ) {
 			$max_width = min( intval( $content_width ), $max_width );
@@ -806,7 +806,7 @@ function image_get_intermediate_size( $post_id, $size = 'thumbnail' ) {
  * @return array Returns a filtered array of image size strings.
  */
 function get_intermediate_image_sizes() {
-	$default_sizes    = array( 'thumbnail', 'medium', 'medium_large', 'large' );
+	$default_sizes    = array( 'thumbnail', 'medium', 'medium_large', 'large', 'extra_large' );
 	$additional_sizes = wp_get_additional_image_sizes();

 	if ( ! empty( $additional_sizes ) ) {
@@ -1200,10 +1200,10 @@ function wp_calculate_image_srcset( $size_array, $image_src, $image_meta, $attac
 	 *
 	 * @since 4.4.0
 	 *
-	 * @param int   $max_width  The maximum image width to be included in the 'srcset'. Default '1600'.
+	 * @param int   $max_width  The maximum image width to be included in the 'srcset'. Default '2624'.
 	 * @param array $size_array Array of width and height values in pixels (in that order).
 	 */
-	$max_srcset_image_width = apply_filters( 'max_srcset_image_width', 1600, $size_array );
+	$max_srcset_image_width = apply_filters( 'max_srcset_image_width', 2624, $size_array );

 	// Array to hold URL candidates.
 	$sources = array();
diff --git src/wp-includes/version.php src/wp-includes/version.php
index 350c2676d7..5110c574af 100644
--- src/wp-includes/version.php
+++ src/wp-includes/version.php
@@ -20,7 +20,7 @@ $wp_version = '5.3-alpha-45282-src';
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 45805;
+$wp_db_version = 45806;

 /**
  * Holds the TinyMCE version
