momen2009

It is plug-in which displays file size on the list of Media Library.

Display Attached File Size

It is plug-in which displays file size on the list of Media Library.

Jason Tucker

This plugin will display the images defined using add_image_size in function.php and from installed plugins. Values are displayed in the Media Settings screen. 
You can see how images are https://codex.wordpress.org/Function_Reference/add_image_size
This plugin is based on the plugin: “Image sizes in admin dashboard!” by mansoormunib

Display Registered Image Dimensions

This plugin will display the images defined using add_image_size in function.php and from installed plugins. Values are displayed in the Media Setting …

Display Attached File Size vs Display Registered Image Dimensions