center aligning a fixed position div

Question

I\'m trying to get a div that has position:fixed center aligned on my page.

I\'ve always been able to do it with absolutely positioned divs using this \

Answer 1

This works if you want the element to span across the page like another navigation bar.

width: calc (width: 100% - width whatever else is off centering it)

For example if your side navigation bar is 200px:

width: calc(100% - 200px);