Sometimes it’s helpful to know about how many words will fit into what time. Here are some general guidelines.
A 30 second spot can have between 60 and 90 words. 60 words could have a dramatic feel, lots of space for emphasizing different words, slight pauses between sentences. 75 words is an average paced read. 90 words would sound somewhere between a car spot and a bank disclaimer.
Doubling those counts for a 60 second spot, we get a range of 120 to 180 words, with 120 sounding open and easy, 150 words being an average paced read, and 180 presenting a very fast read that may be difficult to convey emotion. Too many words resulting in a very fast read can take away from the listeners ability to stay tuned in and retain the message.
The best way to time out your script is with a stopwatch, and the important part: you must read out loud, since we read faster in our head.