diff --git a/src/wp-includes/media.php b/src/wp-includes/media.php
index 9cf301e95c..38ec2213b7 100644
--- a/src/wp-includes/media.php
+++ b/src/wp-includes/media.php
@@ -2117,6 +2117,13 @@ function wp_img_tag_add_width_and_height_attr( $image, $context, $attachment_id
 		$size_array = wp_image_src_get_dimensions( $image_src, $image_meta, $attachment_id );
 
 		if ( $size_array ) {
+			// If the width is enforced through style (e.g. in an inline image), calculate the dimension attributes.
+			$style_width = preg_match( '/style="width:\s*(\d+)px;"/', $image, $match_width ) ? (int) $match_width[1] : 0;
+			if ( $style_width ) {
+				$size_array[1] = (int) round( $size_array[1] * $style_width / $size_array[0] );
+				$size_array[0] = $style_width;
+			}
+
 			$hw = trim( image_hwstring( $size_array[0], $size_array[1] ) );
 			return str_replace( '<img', "<img {$hw}", $image );
 		}
diff --git a/tests/phpunit/tests/media/wpImgTagAddWidthAndHeightAttr.php b/tests/phpunit/tests/media/wpImgTagAddWidthAndHeightAttr.php
new file mode 100644
index 0000000000..84bfc7cc7e
--- /dev/null
+++ b/tests/phpunit/tests/media/wpImgTagAddWidthAndHeightAttr.php
@@ -0,0 +1,85 @@
+<?php
+
+/**
+ * Tests for the `wp_img_tag_add_width_and_height_attr()` function.
+ *
+ * @group media
+ * @covers ::wp_img_tag_add_width_and_height_attr
+ */
+class Tests_Media_Wp_Img_Tag_Add_Width_And_Height_Attr extends WP_UnitTestCase {
+
+	protected static $attachment_id;
+	protected static $attachment_width;
+	protected static $attachment_height;
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		$file                    = DIR_TESTDATA . '/images/2007-06-17DSC_4173.JPG';
+		self::$attachment_id     = $factory->attachment->create_upload_object( $file );
+		self::$attachment_width  = 680;
+		self::$attachment_height = 1024;
+	}
+
+	public static function tear_down_after_class() {
+		wp_delete_attachment( self::$attachment_id, true );
+		parent::tear_down_after_class();
+	}
+
+	/**
+	 * Tests that `wp_img_tag_add_width_and_height_attr()` adds dimension attributes to an image when they are missing.
+	 *
+	 * @ticket 50367
+	 */
+	public function test_add_width_and_height_when_missing() {
+		$image_tag = '<img src="' . wp_get_attachment_image_url( self::$attachment_id, 'full' ) . '">';
+
+		$this->assertSame(
+			'<img width="' . self::$attachment_width . '" height="' . self::$attachment_height . '" src="' . wp_get_attachment_image_url( self::$attachment_id, 'full' ) . '">',
+			wp_img_tag_add_width_and_height_attr( $image_tag, 'the_content', self::$attachment_id )
+		);
+	}
+
+	/**
+	 * Tests that `wp_img_tag_add_width_and_height_attr()` does not add dimension attributes when disabled via filter.
+	 *
+	 * @ticket 50367
+	 */
+	public function test_do_not_add_width_and_height_when_disabled_via_filter() {
+		add_filter( 'wp_img_tag_add_width_and_height_attr', '__return_false' );
+		$image_tag = '<img src="' . wp_get_attachment_image_url( self::$attachment_id, 'full' ) . '">';
+
+		$this->assertSame(
+			$image_tag,
+			wp_img_tag_add_width_and_height_attr( $image_tag, 'the_content', self::$attachment_id )
+		);
+	}
+
+	/**
+	 * Tests that `wp_img_tag_add_width_and_height_attr()` does not add dimension attributes to an image without src.
+	 *
+	 * @ticket 50367
+	 */
+	public function test_do_not_add_width_and_height_without_src() {
+		$image_tag = '<img>';
+
+		$this->assertSame(
+			$image_tag,
+			wp_img_tag_add_width_and_height_attr( $image_tag, 'the_content', self::$attachment_id )
+		);
+	}
+
+	/**
+	 * Tests that `wp_img_tag_add_width_and_height_attr()` respects the style attribute from the inline image format to
+	 * correctly set width and height based on that.
+	 *
+	 * @ticket 59352
+	 */
+	public function test_consider_inline_image_style_attr_to_set_width_and_height() {
+		// '85px' is the original width (680px) divided by 8, so the expected height is equivalently 1024/8=128.
+		$image_tag = '<img src="' . wp_get_attachment_image_url( self::$attachment_id, 'full' ) . '" style="width: 85px;">';
+
+		$this->assertSame(
+			'<img width="85" height="128" src="' . wp_get_attachment_image_url( self::$attachment_id, 'full' ) . '" style="width: 85px;">',
+			wp_img_tag_add_width_and_height_attr( $image_tag, 'the_content', self::$attachment_id )
+		);
+	}
+}