Generated by SassMeister.com.

DrodownHeight-v1.js

// here we set a class "itemcount-[number]" in order to calculate the height in Sass for the height (= padding-bottom) of the submenu
$(function() {
  // "use strict";
  var nmbrItemsHome = ($("#tt-home li").length);
  var nmbrItemsBlog = ($("#tt-blog li").length);
  var nmbrItemsBooks = ($("#tt-books li").length);
  var nmbrItemsGoodies = ($("#tt-goodies li").length);
  var nmbrItemsMedia = ($("#tt-media li").length);
  var nmbrItemsNews = ($("#tt-news li").length);
  var nmbrItemsContact = ($("#tt-contact li").length);
  $('#tt-home').addClass('tt-nav__itemcount-'+nmbrItemsHome);
  $('#tt-blog').addClass('tt-nav__itemcount-'+nmbrItemsBlog);
  $('#tt-books').addClass('tt-nav__itemcount-'+nmbrItemsBooks);
  $('#tt-goodies').addClass('tt-nav__itemcount-'+nmbrItemsGoodies);
  $('#tt-media').addClass('tt-nav__itemcount-'+nmbrItemsMedia);
  $('#tt-news').addClass('tt-nav__itemcount-'+nmbrItemsNews);
  $('#tt-contact').addClass('tt-nav__itemcount-'+nmbrItemsContact);
}); 

DrodownHeight-v2.js

$(function() {
  var itms = {
  home    : ($("#tt-home li").length),
  blog    : ($("#tt-blog li").length),
  books   : ($("#tt-books li").length),
  goodies : ($("#tt-goodies li").length),
  media   : ($("#tt-media li").length),
  news    : ($("#tt-news li").length),
  contact : ($("#tt-contact li").length)
  };

 jQuery.each( itms, function( i, val ) {
   $( "#tt-" + i ).addClass('tt-nav__itemcount-'+val);
 });

});  

DropdownHeight-SassMeister-input.scss

// ----
// Sass (v3.4.4)
// Compass (v1.0.1)
// ----

$tt-nav-breakpoint: 55em;   
$item-count-list: 1 2 3 4 5 6 7 8 9 10;
$item-value-list: 46px 92px 138px 184px 230px 276px 322px 368px 414px 460px;
// declarations for small screen
@for $i from 1 through length($item-count-list) {
  .is-active[class*="itemcount-#{$i}"] .tt-nav__submenu {
   @media (max-width: $tt-nav-breakpoint) {  
      padding-bottom: nth($item-value-list, $i);
   }
  }
}
// declarations for wide screen
@for $i from 1 through length($item-count-list) {
  [class*="itemcount-#{$i}"]:hover .tt-nav__submenu {
    @media (min-width: $tt-nav-breakpoint) {  
      padding-bottom: nth($item-value-list, $i);
   }
  }
}

DropdownHeight-SassMeister-output.css

@media (max-width: 55em) {
  .is-active[class*="itemcount-1"] .tt-nav__submenu {
    padding-bottom: 46px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-2"] .tt-nav__submenu {
    padding-bottom: 92px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-3"] .tt-nav__submenu {
    padding-bottom: 138px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-4"] .tt-nav__submenu {
    padding-bottom: 184px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-5"] .tt-nav__submenu {
    padding-bottom: 230px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-6"] .tt-nav__submenu {
    padding-bottom: 276px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-7"] .tt-nav__submenu {
    padding-bottom: 322px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-8"] .tt-nav__submenu {
    padding-bottom: 368px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-9"] .tt-nav__submenu {
    padding-bottom: 414px;
  }
}

@media (max-width: 55em) {
  .is-active[class*="itemcount-10"] .tt-nav__submenu {
    padding-bottom: 460px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-1"]:hover .tt-nav__submenu {
    padding-bottom: 46px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-2"]:hover .tt-nav__submenu {
    padding-bottom: 92px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-3"]:hover .tt-nav__submenu {
    padding-bottom: 138px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-4"]:hover .tt-nav__submenu {
    padding-bottom: 184px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-5"]:hover .tt-nav__submenu {
    padding-bottom: 230px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-6"]:hover .tt-nav__submenu {
    padding-bottom: 276px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-7"]:hover .tt-nav__submenu {
    padding-bottom: 322px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-8"]:hover .tt-nav__submenu {
    padding-bottom: 368px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-9"]:hover .tt-nav__submenu {
    padding-bottom: 414px;
  }
}

@media (min-width: 55em) {
  [class*="itemcount-10"]:hover .tt-nav__submenu {
    padding-bottom: 460px;
  }
}

DropdownHeight.html

<!DOCTYPE html>
<html>

<head>

  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <title>Responsive Nav</title>

    <link rel="stylesheet" href="css/style.css" media="screen" type="text/css" />

</head>

<body>

<nav class="tt-nav" id="js-tt-nav">

  <ul class="tt-nav__list">

    <li class="tt-nav__item is-active" id="tt-home"><a href="/" class="tt-nav__link">Home</a>
    <ul class="tt-nav__submenu submenu-first">
      <li><a href="">Home</a></li>
      <li><a href="awards.htm">Awards</a></li>
      <li><a href="beyond.htm">Beyond</a></li>
      <li><a href="beyondchildren.htm">Beyond Children</a></li>
      <li><a href="beyondlovewithin.htm">Beyond Love Within</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-blog">
    <a href="/" class="tt-nav__link">Blog</a>
    <ul class="tt-nav__submenu">
      <li><a href="blog/" target="_blank">Blog</a></li>
      <li><a href="biography.htm">Biography</a></li>
      <li><a href="interview.htm">Interviews</a></li>
      <li><a href="links.htm">Links</a></li>
      <li><a href="lyrics.htm">Lyrics</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-books"><a href="/" class="tt-nav__link">Books</a>
    <ul class="tt-nav__submenu">
      <li><a href="books.htm">Books</a></li>
      <li><a href="magazine.htm">Magazines</a></li>
      <li><a href="flagggroveschool.htm">Flagg Grove School</a></li>
      <li><a href="magazine.htm">Magazines</a></li>
      <li><a href="mycollection.htm">My Collection</a></li>
      <li><a href="songbooks.htm">Songbooks</a></li>
      <li><a href="tourbooks.htm">Tourbooks</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-goodies">
    <a href="/" class="tt-nav__link">Goodies	</a>
    <ul class="tt-nav__submenu">
      <li><a href="drawings.htm">Drawings</a></li>
      <li><a href="ecards.htm">Ecards</a></li>
      <li><a href="fanmap.htm">Fanmap</a></li>
      <li><a href="fanstina.htm">Fans-Tina</a></li>
      <li><a href="general.htm">General</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-media">
    <a href="/" class="tt-nav__link">Media</a>
    <ul class="tt-nav__submenu">
      <li><a href="albums.htm">Albums</a></li>
      <li><a href="albums-extended.htm">Albums-Extended</a></li>
      <li><a href="7inchsingles.htm">7 Inch Singles</a></li>
      <li><a href="maxisingles.htm">12 Inch Maxi Singles</a></li>
      <li><a href="singles.htm">CD Singles</a></li>
      <li><a href="dvd-vhs-blu-ray.htm">DVD-VHS-Blu-Ray</a></li>
      <li><a href="dvd-vhs-others.htm">Videos with others</a></li>
      <li><a href="lp.htm">LP's</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-news"><a href="/" class="tt-nav__link">News</a>
    <ul class="tt-nav__submenu">
      <li><a href="news.php">News</a></li>
      <li><a href="filmography.htm">Film</a></li>
      <li><a href="photos.htm">Photos</a></li>
      <li><a href="tourphotos.htm">Tour Photos ’08-’09</a></li>
      <li><a href="tourdates.htm">Tours</a></li>
      <li><a href="videos.htm">Videos</a></li>
    </ul>
    </li>
    <li class="tt-nav__item" id="tt-contact"><a href="/" class="tt-nav__link">Contact</a>
    <ul class="tt-nav__submenu submenu-last">
      <li><a href="contact.php">Contact</a></li>
      <li><a href="http://goo.gl/uk8Ubp" target="_blank">Appearances</a></li>
      <li><a href="credits.htm">Credits</a></li>
      <li><a href="donation.htm">Donation</a></li>
      <li><a href="forum/" target="_blank">Forum</a></li>
    </ul>
    </li>
  </ul>
</nav>

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>window.jQuery || document.write('<script src="../../../../js/lib/jquery-1.11.1.min.js"><\/script>')</script>
<script src="js/index.js"></script>
</body>

</html>