blog/_includes/functions/get_reading_time.html

{% if include.params.article %}
  {% assign article = include.params.article %}
{% endif %}

{% if include.params.speed %}
  {% assign speed = include.params.speed %}
{% else %}
  {% assign speed = 160 %}
{% endif %}

{% assign total_mins = article
  | number_of_words
  | divided_by: speed
  | at_least: 1 %}

{% assign hours = total_mins | divided_by: 60 %}
{% assign mins = total_mins | modulo: 60 %}

{% assign return = "About" %}

{% if hours > 0 %}
  {% assign unit = "hour" %}
  {% if hours > 1 %}
    {% assign unit = unit | append: "s" %}
  {% endif %}
  {% assign return = return
    | append: " "
    | append: hours
    | append: " "
    | append: unit %}
{% endif %}

{% assign unit = "min" %}
{% if mins > 1 %}
  {% assign unit = unit | append: "s" %}
{% endif %}
{% assign return = return
  | append: " "
  | append: mins
  | append: " "
  | append: unit %}