Talking about voice actor: Brazilian voices speak at an average speed of 141 words per minute. Many corporate film makers try to keep a maximum length of 1 to 1.30 minutes, so that most scripts will contain less than 200 words.
Writing words per minute
It is of course not easy for everyone to write a limited number of words per minute for your voice-over. Especially if you want to stay under 90 seconds. But luckily there are a number of tricks to keep up the speed, and the most important is: don't put too much emphasis on every word.
We often see voice-over scripts in which many words per sentence are underlined, with the intention of putting extra emphasis on this because these words are considered important by the company. But did you know that you should never emphasize more than 1 or 2 words per sentence? And rather emphasize 1 than 2 words per sentence, so really only emphasize 2 words in a sentence if there really is no other option.
Be careful with breaks & use them wisely!
Certainly with corporate films and training videos we often see scripts in which a new item is always shown, and then there is silence for a few seconds. This brings the tempo of the voice-over down enormously, and therefore also of your film. It is better to only use a short silence at the beginning of your film. For example, by asking a question (short silence) and then giving the answer. Then try to keep the voiceover below 140 words per minute for the rest of your movie. Good luck!