So in case you are wondering how I modified the default Twenty Fourteen (as of 2016) theme all I did was add in the following custom CSS in the “Edit CSS” section under appearance.

.site, .site-header, .page-content, article header, .entry-header, .entry-content, .entry-summary, .entry-meta, .comments-area, nav.navigation.post-navigation {
max-width: inherit !important;
}