ReadingTime.html

{% capture truncated_content %}{{ page.content | truncatewords: 250 }}{% endcapture %}
{% if page.content != truncated_content %}
Reading time ~<span class="time">{{ page.content | number_of_words | append: '.0' | divided_by:180 }}</span>min.
{% endif %}

Round.js

<script type='text/javascript'>
  $(document).ready(function() {
    $(".time").text(function (index, value) {
      return Math.round(parseFloat(value));
    });
  });
</script>