Subtitle calculators
Subtitle duration calculator
Paste subtitle text and a reading-speed target to find the minimum time the cue needs on screen.
To keep 0 characters at 20 CPS, the cue needs at least 0.00 seconds. The Netflix maximum is 7 seconds.
How this is calculated
Minimum display time is the visible character count divided by your reading-speed target. It is the shortest time a cue can stay up and still read at that speed — extend it into silence rather than holding it over the next line of dialogue.
Reading-speed limits to compare against
Netflix allows up to 20 CPS for adult and 17 CPS for children's programs, with a 42-character line and a two-line maximum. For a full-file check, use the subtitle reading speed checker.
Questions editors ask
Which reading speed should I choose?
The reference English presets are based on Netflix's English (USA) guide: 20 CPS for adult programs and 17 for children's programs. Languages and clients use different limits. Set the thresholds required by your project.
Do spaces, tags, and line breaks count?
Spaces and punctuation inside a subtitle line count. Formatting tags are removed. Line-break separators are excluded. Counts use Unicode code points, rather than JavaScript string length; some emoji and combined letters use several code points.
Does CueCheck change my subtitles?
No. It reports potential readability and timing issues. Your original file stays unchanged. The downloadable CSV is a review checklist for your subtitle editor.
Can I check subtitles in another language?
Yes, Unicode text is supported. The provided thresholds are for English, so enter appropriate values for your target language and audience. This tool does not evaluate translation quality.
What information is collected?
Your subtitles and filenames stay local. Anonymous tool-page visits and control clicks help improve the site. You can disable that measurement on the privacy page.