When you embed images in your WordPress posts and pages, they’ll have the default sizes to select and display from. You can change the default height and width for your embedded content and add a custom size of your choice.
Instructions: Add the following code to the functions.php file of your WordPress theme.
You can replace the height and width in the following code.
function wps_embed_size($embed_size){
if(is_single()){
$embed_size['height'] = 240;
$embed_size['width'] = 380;
}
return $embed_size;
}
add_filter('embed_defaults', 'wps_embed_size');
You may also enjoy removing WordPress oEmbed related items.
Nice post