Get value of a field attached to a user entity based on currently logged in user
global $user;
// Only if logged in
if($user-&gt;uid) {
  $logged_in_user = user_load($user-&gt;uid);
  $field_user_class = field_get_items('user', $logged_in_user, 'field_user_class');
  // Do stuff with array $field_user_class
}