How do you calculate video length from a script?
The calculation is based on average reading speeds, measured in Words Per Minute (WPM). While casual conversational speaking sits around 120-150 WPM, YouTube voiceovers are typically denser and faster to maintain viewer retention.
- Documentaries / Mysteries: Slower pacing (130 WPM) allows for dramatic pauses and atmospheric tension.
- Educational / Stories: Standard pacing (150 WPM) keeps the viewer engaged while ensuring the information is easily digested.
- Tech / Finance / Cash Cow: Fast pacing (170 WPM) is crucial to prevent drop-off in highly competitive, information-dense niches.
- YouTube Shorts / TikToks: Extremely fast pacing (190+ WPM) is required to hook scrollers and deliver maximum value in under 60 seconds.
The perfect script length for a 10-minute video
If your goal is to monetize via YouTube AdSense, hitting the 8-minute mark (which allows for mid-roll ads) is essential. To comfortably reach 8 to 10 minutes at a normal reading pace, you should aim for a script between 1,200 and 1,500 words.