SRT duration calculator
Upload or paste subtitles to see total runtime, cue count, and average reading speed — useful before delivery QC or platform upload.
Paste or upload a subtitle file to see total runtime, cue count, and average reading speed.
Need per-cue CPS flags? Use the reading speed checker. Need to shift timing? Shift subtitle timing.
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Frequently asked
How do I find the total length of an SRT file?+
Total span is from the first cue start to the last cue end — not the sum of individual cue durations (gaps between cues are excluded). This tool parses SRT and VTT and reports that span instantly.
Does total span equal video length?+
Only if captions cover the full video. Trailers and social clips often have captions only on spoken sections — compare span to your video runtime separately.
What is average CPS?+
Characters per second per cue, averaged across the file. Netflix targets ≤17 CPS for adult English; this tool flags averages above that threshold.
Can I convert after checking duration?+
Yes — use our SRT to VTT, SRT to TXT, or JSON converters on the free tools page once timing looks right.