AI Ad Voiceovers: 15, 30 and 60-Second Scripts
How long an ad script should be for 15, 30 and 60 seconds, a structure that works for each, three example scripts and how to test voices before you spend.
By the MCV Labs team · · 6 min read
Ads have no time to waste, so the script length matters more than anything else. Spoken at a natural pace, people say about two and a half words a second. Use that to size your script before you generate a single take.
How many words fit
- 15 seconds: about 35–40 words.
- 30 seconds: about 70–75 words.
- 60 seconds: about 140–150 words.
Leave a second or two of silence for the logo or end card. Read the script aloud with a timer once before generating.
A structure for each length
- 15 seconds: hook → one benefit → call to action.
- 30 seconds: hook → problem → solution → proof → call to action.
- 60 seconds: hook → problem → solution → two or three benefits → proof → offer → call to action.
Three example scripts
The examples use BrewBox, a made-up coffee brand — swap in your own product.
15 seconds (34 words): “Running late again? BrewBox delivers fresh coffee beans to your door every two weeks, roasted the day they ship. Pick your roast, skip any delivery, cancel anytime. Try BrewBox today at brewbox dot com.”
30 seconds (71 words): “Your morning coffee shouldn't taste like it's been on a shelf for months. Most supermarket beans were roasted long before you buy them. BrewBox roasts to order and ships the same day, so every bag arrives fresh. Choose from light, medium or dark roasts, change your plan whenever you like, and skip a delivery in one tap. Fresh coffee, on your schedule. Start your first box today at brewbox dot com.”
For 60 seconds, extend the 30-second script with a second benefit, a short customer quote you actually have permission to use, and a clear offer — then repeat the call to action.
Write for the ear
- Write website addresses the way they're said (“brewbox dot com”).
- Write prices and numbers as you want them heard.
- Use full stops for pauses before the call to action.
- Avoid tongue-twisters and long lists of features.
Test voices before you spend
Use “Preview first line” to hear the hook in three voices, pick one, then generate the full spot. If the offer changes later, regenerate only that sentence. Keep the same voice across a campaign so the ad, the demo and the social cut-downs sound like one brand.
Rights and disclosure
Paid ads are commercial use, which MCV Labs includes on paid plans, subject to the voice licence. Some ad platforms and countries require AI-generated audio to be disclosed — follow their rules — and never use a voice that imitates a real person without their consent.