Get the estimated reading time of an article, blog post, or custom post in WordPress

get_estimated_reading_time.php

<?php

/**
 * get_estimated_reading_time --- Get estimated reading time in minutes
 * @author Vincent V. Toscano
 * Created by Vincent on Oct. 19, 2020
 * Updated Oct. 20, 2020
 * Ref.: get_the_content https://developer.wordpress.org/reference/functions/get_the_content/
 * Ref.: strip_shortcodes https://developer.wordpress.org/reference/functions/strip_shortcodes/
 * Ref.: strip_tags https://www.php.net/manual/en/function.strip-tags.php
 * @param   string $content Feed the method your copy/content/string
 * @param   int $wpm Typical/average words per minute 200 to 400 wpm
 * @return  false|float
 * @example <?php $readTime = get_estimated_reading_time( get_the_content() ); ?>
 *          <time datetime="P<? echo $readTime?>M"><? echo $readTime?> minute<?php if ($readTime > 1)echo 's'; ?></time>
 */
function get_estimated_reading_time( $content = '', $wpm = 250 ) {
	$cleaned_content = strip_tags( strip_shortcodes( $content ) );
	$word_count = str_word_count( $cleaned_content );
	$time = ceil( $word_count / $wpm );
	return $time;
}

Initial function with examples

Used to estimate the reading time based on length of article or post and the chosen words per minute param.

Updated comment and example to use echo