Change number of posts on category pages

To change the number of blog posts that display on each category page:

1. Go to WordPress > Appearance > Theme Editor > Functions.php.

2. Find this section:

//* Change number of posts on category archive pages
function child_cat_query( $query ) {
if ( $query->is_archive() && $query->is_main_query() && !is_admin() ) {
        $query->set( 'posts_per_page', 6 );
    }
}
add_action( 'pre_get_posts', 'child_cat_query' );
Please note this section will vary between themes. "child" will actually say the name of your theme, i.e. "amelia." Your number "6" may be "12" or "15." The same instructions will apply.

3. On this line:

$query->set( 'posts_per_page', 6 );

Replace the number (6 in the example above) with your desired number of posts. Be careful to ONLY change the number and nothing else.

4. Click Update File to save.