[@robkk Moderator 11 years ago]

You can use the tag cloud widget, select the taxonomy to be topic tags, then use this PHP function in your child theme or in a functionality plugin.

add_filter('widget_tag_cloud_args','set_tag_cloud_sizes');
function set_tag_cloud_sizes($args) {
$args['smallest'] = 12;
$args['largest'] = 19;
return $args; }