Centering a ul submenu

Question

i have been working on this sub-menu for 8 hours now, the last little thing i cant figure out is how to do is to center the li items (or the ul item) in the sub-menu. Maby this picture helps:

I need to center all the li items under the blue arrow. This is my code for the ul ul and ul ul li. Please leave a comment if you need more information, all tips hints and ofc. answers are appreciated :)

 /*
 *
 * Menu
 *
 */
#access {
    display: block;
    width: 46.4em;
    float: right;
    height: 7.3em;
    line-height: 7.3em;
    margin: 0 1.5em 0 0;
}
#access ul {
    list-style: none;
    margin: 0;
    padding-left: 0;
    text-align: center;
}
#access li {
    float: left;
    padding: 0 2em;
}
#access a {
    position: relative;
    height: 73px;
    font-size: 1.4em;
    display: block;
    line-height: 5.071428571em;
    font-family: Georgia, Times New Roman, serif;
    text-transform: uppercase;
    color: #009cda;
}
.current-menu-item {
    background: url("images/arrow.png") no-repeat;
    background-position: 50% 100%;
}
.current-cat-menu-item  a {
    text-decoration: underline;
}
ul li .current-menu-item{
    background: none;
}
.current-menu-item.parent-item  a:hover {
    background: url("images/arrow-blue.png") no-repeat;
    background-position: 50% 229%;
}
#access ul ul {
    display: none;
    top: 100%;
    z-index: 998;
    position: absolute;
    height: 36px;
    text-align: center;
}
#access ul ul li{
    display: inline;
    list-style: none;
}
#access ul ul a {
    color: #fff;
    font-size: 12px;
    line-height: 3em;
    height: auto;
    z-index: 1000;
    text-transform: none;
    font-family: Arial, sans-serif;
}
#access li:hover > a,
#access ul ul :hover > a {
    text-decoration: underline;
}
#access .parent-item:hover > a  {
    background: url("images/arrow-blue.png") no-repeat;
    background-position: 50% 229%;
    z-index: 999;
}
#access ul ul :hover > a {
        background: none;
}
#access ul li:hover > ul {
    display: block;
}
.sub-menu-wrapper {
    display: none;
    width: 100%;
    height: 36px;
    top: 71px;
    left: 0;
    position: absolute;
    background: url("images/blue.png") repeat-x bottom;
    z-index: 997;
    /* #009CDA;
    -webkit-box-shadow: inset 0px -1px 5px 0px rgba(0, 0, 0, 0.3);
    -moz-box-shadow: inset 0px -1px 5px 0px rgba(0, 0, 0, 0.3);
    box-shadow: inset 0px -1px 5px 0px rgba(0, 0, 0, 0.3);  */
}
#access ul li:hover > span {
    display: block;
}

This is my html structure:

<nav class="menu-topp-meny-container">
    <ul id="menu-topp-meny" class="menu">
        <li id="menu-item-116" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-116">
            <a href="http://test3.clydemarketing.com/om-monster-2/">Om Monster</a>
        </li>
        <li id="menu-item-225" class="menu-item menu-item-type-post_type menu-item-object-page current-menu-item page_item page-item-171 current_page_item current-menu-ancestor current-menu-parent current_page_parent current_page_ancestor menu-item-225 parent-item">
            <a href="http://test3.clydemarketing.com/entertainment/om-oss/">Avdelinger</a>
            <ul class="sub-menu">
                <li id="menu-item-254" class="menu-item menu-item-type-post_type menu-item-object-page current-page-ancestor current-page-parent menu-item-254">
                    <a href="http://test3.clydemarketing.com/entertainment/">Entertainment</a>
                </li>
                <li id="menu-item-260" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-260">
                    <a href="http://test3.clydemarketing.com/entertainment/kontakt/">Kontakt</a>
                </li>
                <li id="menu-item-261" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-261">
                    <a href="http://test3.clydemarketing.com/entertainment/arkiv/">Arkiv</a>
                </li>
                <li id="menu-item-262" class="menu-item menu-item-type-post_type menu-item-object-page current-menu-item page_item page-item-171 current_page_item menu-item-262">
                    <a href="http://test3.clydemarketing.com/entertainment/om-oss/">Om Oss</a>
                </li>
            </ul>
        <span class="sub-menu-wrapper"></span>
        </li>
        <li id="menu-item-26" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-26">
            <a href="http://test3.clydemarketing.com/kontakt/">Kontakt</a>
        </li>
        <li id="menu-item-25" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-25">
            <a href="http://test3.clydemarketing.com/jobb/">Jobb</a>
        </li>
    </ul>
</nav>

Answer 1

Calculate the total width of all li items you have and add this to your ul's css:

var total = 0;
$('li').each(function(){
    total += $(this).width();
});
$('ul').css({
    'width': total + 'px',
    'margin': '0px auto'
});

Answer 2

Try somthing like this in the css:

#nav_row li#menu-item li.menu-item 
{
padding-bottom:10px !important;
float:none !important;
text-align:center;
}