The easiest method for including google +1 button on your web page is to include the necessary JavaScript resource and to add a +1 button tag.
Just add below tag into your HTML where you want to put google +1 button.
<!-- Place this tag where you want the +1 button to render. --> <div class="g-plusone"></div>
Add below java script into your head section.
<script type="text/javascript"> (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })(); </script>
That’s it.
You can find all other parameters at https://developers.google.com/+/plugins/+1button/