jQuery smooth scroll to anchor minus set amount of pixels

Please add this code in footer.php file of your active theme just above closing body tag (</body>).

<script type="text/javascript">
jQuery(document).ready(function($) {
	$(function() {
	  $('a[href*=#]:not([href=#])').click(function() {
		if (location.pathname.replace(/^\//,'') == this.pathname.replace(/^\//,'') && location.hostname == this.hostname) {
		  var target = $(this.hash);
		  target = target.length ? target : $('[name=' + this.hash.slice(1) +']');
		  if (target.length) {
			$('html,body').animate({
			  scrollTop: target.offset().top-100
			}, 1000);
			return false;
		  }
		}
	  });
	});
});
</script>

For any questions, feel free to ask me in comments.