There are several ways to answer this. According to the “National Centre for Voice and Speech” the average rate of speech for English speakers is 150 words per minute. Divide that in half and you have an answer of 75 words per 30 seconds. Easy right? But then why are there so many words in this article? Well, because that only answers the average word counts.
Your radio commercial might not be effective if read at the average speed. Your message could be a hard sell and will be effectively read with urgency (90 words per 30 seconds), or your message could have a somber or thought-provoking tone that would need a more deliberate read (60 words per 30 seconds).
Something else to consider if you’re using a word count to write your radio commercial is that a number is not a word. Your computer may think your phone number (555-555-5555) is a single word when counted, but when read out loud it is actually 10! This goes for pricing (i.e. $19.99 = “nineteen dollars and ninety nine cents”) and addresses (i.e. 1334 44th Street = “thirteen thirty four, forty fourth street”).
Finally, the words you use make a big difference. More syllables means more time.
Here’s an example:
Get out your stopwatch app on your phone and time yourself on how many seconds it takes to read the following 10 word sentences.
1. “The duck flew at night to steer clear of light.”
2. “Mallards routinely circumnavigate evening skies to ultimately evade daytime luminosity.”
The second sentence should have been double the time to read as the first sentence.
All this may seem daunting and complicated, but there’s still a simple answer to “how many words are in a 30 second radio commercial?” Time it. That same stopwatch used above is the most important tool you have for proofing your copy. Read your script out loud the way you want it read and time it. If it’s 30 seconds, you’re done. If it’s long or short, you have more editing to do.
The last thing you want is to have is a message that is too long and needs to be speed-read. The audience will tune out and your business will not see results from your advertising.
Article Courtesy of Paul Brain
Paul has been writing and producing radio commercials for over 16 years, and is currently the Creative Director for Bell Media in the BC interior.