<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<button type="button" class="btn btn-default btn-circle">5</button>
<button type="button" class="btn btn-primary btn-circle">5</button>
<button type="button" class="btn btn-success btn-circle">5</button>
<button type="button" class="btn btn-info btn-circle">5</button>
<button type="button" class="btn btn-warning btn-circle">5</button>
<button type="button" class="btn btn-danger btn-circle">5</button>
<h2>lg</h2>
<button type="button" class="btn btn-default btn-circle btn-lg">10</button>
<button type="button" class="btn btn-primary btn-circle btn-lg">10</button>
<button type="button" class="btn btn-success btn-circle btn-lg">10</button>
<button type="button" class="btn btn-info btn-circle btn-lg">10</button>
<button type="button" class="btn btn-warning btn-circle btn-lg">10</button>
<button type="button" class="btn btn-danger btn-circle btn-lg">10</button>
<h2>xl</h2>
<button type="button" class="btn btn-default btn-circle btn-xl">15</button>
<button type="button" class="btn btn-primary btn-circle btn-xl">15</button>
<button type="button" class="btn btn-success btn-circle btn-xl">15</button>
<button type="button" class="btn btn-info btn-circle btn-xl">15</button>
<button type="button" class="btn btn-warning btn-circle btn-xl">15</button>
<button type="button" class="btn btn-danger btn-circle btn-xl">15</button>
