Simple Emacs function to calculate the speaking time of a selection of text. Replace '150' with your average speaking time.

calc-speaking-time.el

(defun jib/calc-speaking-time ()
  "Calculate how long it would take me to speak aloud the selection."
  (interactive)
  (if (use-region-p) (let* ((wpm 150)
							(word-count (float (count-words-region (region-beginning) (region-end))))
							(raw-time (* 60 (/ word-count wpm))))
					   (message "%s minutes, %s seconds to speak at %d wpm"
								(format-seconds "%m" raw-time)
								(floor(mod raw-time 60)) wpm))
	(error "Error: select a region.")))