Convert subtitles from 29.97 to 25 fps
NTSC television or video content (TV episodes, camcorder footage) converted to PAL. Only relevant when the video was sped up rather than frame-converted — check with two-point sync first.
Move subtitles by a fixed amount when every line is off by the same delay.
Seconds (2.5), milliseconds (1500ms) or a time (00:00:02,500). Subtitles appear too early → Later.
For subtitles that drift. Pick two cues far apart and enter when each should appear.
Rescale times when the subtitle was made for a video with a different frame rate.
The file open now is part 1 / language 1.
Cues
Save options
Output preview
What the conversion does
Converting from 29.97 to 25 fps multiplies every subtitle time by 29.97 ÷ 25 = 1.198801. The subtitles become later by 19.88 % of their time, so the change is zero at the start and largest at the end. The exact NTSC rates are used (23.976 = 24000/1001, 29.97 = 30000/1001).
Drift between 29.97 and 25 fps
| Subtitle time | After conversion | Difference |
|---|---|---|
| 00:10:00 | 00:11:59,281 | +1 min 59 s |
| 00:30:00 | 00:35:57,842 | +5 min 58 s |
| 00:45:00 | 00:53:56,763 | +8 min 57 s |
| 01:00:00 | 01:11:55,684 | +11 min 56 s |
| 01:30:00 | 01:47:53,526 | +17 min 54 s |
| 02:00:00 | 02:23:51,369 | +23 min 51 s |
A 120-minute film timed at 29.97 fps runs 23 min 51 s longer at 25 fps.
How to convert subtitles from 29.97 to 25 fps
- Open the subtitle file. Drop the subtitle file that drifts on the tool.
- Check the frame rates. “Subtitle made for” is set to 29.97 fps and “Video plays at” to 25 fps.
- Convert. Click Convert frame rate, then compare a line near the end with the video.
- Save. Download in SRT, VTT, ASS or TXT.
Other frame-rate conversions
Background: why subtitles drift between frame rates. Not sure of the rates? Use two-point sync — it detects the ratio for you.
FAQ
How much do subtitles drift between 29.97 and 25 fps?
19.88 % of the running time: 1 min 59 s after 10 minutes and 11 min 56 s after an hour.
What is the conversion factor from 29.97 to 25 fps?
Every time is multiplied by 29.97 ÷ 25 = 1.198801. A subtitle at 01:00:00 moves to 01:11:55,684.
How do I know this is the right fix?
If the subtitles are close at the start and the error grows steadily, it is a speed mismatch. If the error is the same everywhere, use Shift instead.