How do I calculate the offsets for pagination?

Question

I am working on a pagination feature in a web service I am writing, but my lack of math insight is killing me now. I have a couple of keys: totalItems, cu

Answer 1

For here I'm used code below and works fine.

 $offset,
      'post_type' => 'post',
      'posts_per_page' => 30,
      'category_name'     => $cat_filter,
      'post_status' => 'publish',
      'paged' => $paged
    );

  $query = new WP_Query( $args_2 );

  if ( $query->have_posts() ) :
    while ( $query->have_posts() ) : $query->the_post();
      ?>