I am designing a page using Bootstrap 3. I am trying to use a popover with placement: right on an input element. The new Bootstrap ensures that if you use 
        
I used this(working fine) :
.popover{
   background-color:#b94a48;
   border:none;
   border-radius:unset;
   min-width:100px;
   width:100%;
   max-width:400px;
   overflow-wrap:break-word;
}
                                                                        you can also add the data-container="body" which should do the job :
<div class="row">
    <div class="col-md-6">
        <label for="name">Name:</label>
        <input id="name" class="form-control" type="text" 
                         data-toggle="popover" data-trigger="hover"
                         data-container="body"
                         data-content="My popover content.My popover content.My popover content.My popover content." />
    </div>
</div>
                                                                        In Angular ng-bootstrap you can simply container="body" to the control that triggers popover (such as button or textbox). Then in your global styleing file (style.css or style.scss) file you must add .popover { max-width: 100% !important; }. After that, the content of the popover will automatically set to its content width.
To change width you can use css
For fixed size wanted
.popover{
    width:200px;
    height:250px;    
}
For max width wanted:
.popover{
    max-width:200px;
    height:250px;    
}
jsfiddle: http://jsfiddle.net/Rqx8T/2/
 <label id="txtLbl">Overview</label> <a tabindex="0" class="btn btn-default" role="button" data-toggle="popover"  data-placement="right" id="Pops" ></a>  
<div id="popover-content" class="hide">
  <div class="popovermenu">
        Your content                   
  </div>
 </div>
I end up by setting div "popover-content" width to the number I want. (other ids or class won't work.....) Good luck!
  #popover-content{
      width: 600px;
  }
                                                                        You can change the template of your popover. Either with the data-template-attribute or with the relevant part in the function that sets it up:
<html>
  <head>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
      <!-- Latest compiled and minified CSS -->
      <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
      <!-- Latest compiled and minified JavaScript -->
      <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
  </head>
  <body>
    <span class="text-green" data-toggle="popover" data-placement="right" data-template="<div class="popover fade top in" style="max-width:none;" role="tooltip"><div class="arrow"></div><h3 class="popover-title"></h3><div class="popover-content"></div></div>" data-trigger="manual" data-original-title="Some Title" data-content="<div>Some really long text and stuff. Some really long text and stuff. Some really long text and stuff. Some really long text and stuff.</div>" data-html="true" onclick="$(this).popover('show');">clickme</span>
  </body>
</html>