Add Custom Image Size & Connect Custom Images sizes to WordPress

add-custom-image-size-and-connect-custom-image-sizes-to-wordpress.php

<?php

// Add Custom Image Sizes
add_action( 'after_setup_theme', 'setup_image_sizes' );
function setup_image_sizes() {
    if ( function_exists( 'add_image_size' ) ) {
        add_image_size( 'example-name', 360,214,true );

    }
}
// Connect Custom Image sizes to Wordpress
add_filter('image_size_names_choose', 'post_image_sizes');
function post_image_sizes($sizes){
    $custom_sizes = array(
        'example-name' => 'Example Name',
    );
    return array_merge( $sizes, $custom_sizes );
}

?>