BuddyPress.org

@pcwriter why don’t you just use percentages? If you have a fluid width and set the width of the negative margin-right and the content width.

For example:

div#sidebar {
width: 25%;
float: left;
}

div.content {
float: right;
margin-right: 26%;
}

The code above won’t work, but it’s to give you an idea!