how to control column width bootstrap grid code example

Example: bootstrap fixed column width grid

<nav>...</nav>
<div class="container-fluid">
<div class="row">
  <!-- Use div instead of a column for sidebar -->
<div class="sidebar">
<ul class="nav nav-sidebar">
    <li class="active"><a href="#">Overview</a></li>
    <li><a href="#">Reports</a></li>
    <li><a href="#">Analytics</a></li>
    <li><a href="#">Export</a></li>
</ul>
</div>
<div class="col-sm-12 main">
<h1 class="page-header">Dashboard</h1>
</div>
</div>
</div>