How many characters per second should subtitles use?
17 CPS for adult English content (Netflix). 15 CPS for the BBC. 12 CPS for children's content. Short-form social can push to 20 CPS.
Detail
Characters per second (CPS) is the professional standard for subtitle reading speed. It's calculated as the visible character count of a cue divided by its duration in seconds. Different audiences read at different speeds, and major broadcasters publish their caps. Netflix uses 17 CPS for adult English content. The BBC uses 15 CPS as the editorial cap for adult viewers and drops to 11–12 for children. Theatrical convention historically capped around 20 CPS. Short-form social viewers (TikTok, Reels, Shorts) can comfortably handle 18–20 CPS because they expect a faster pace and can re-read.
| Audience | CPS cap |
|---|---|
| Netflix adult English | 17 |
| BBC adult | 15 |
| BBC children | 11–12 |
| Theatrical | ~20 |
| TikTok / Reels / Shorts | 18–20 |
About 160–200 WPM for adult viewers. Children's content drops to ~140 WPM. WPM is a sanity check; CPS is the primary metric.
A heavy sans-serif. Inter Black, Montserrat Black, and Anton are reliable defaults. Avoid thin fonts — they break apart on compressed video.