Free Tool
Timecode Converter & Calculator
Convert timecodes between seconds, HH:MM:SS, SRT, VTT and SMPTE frames, with 29.97 drop-frame, and add or subtract them on one line. Everything runs in your browser.
- Runs in your browser
- Nothing uploaded
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Supports .srt, .vtt, .txt files
Add SRT files (2+)
Result
How it works
Timecode Converter & Calculator in three steps
Paste timecodes
Enter one value per line in any format: 90, 00:01:30,500, 01:00:00:00 or drop-frame 01:00:00;00.
Pick a frame rate
Each line converts to seconds, SRT, VTT and SMPTE timecode at the rate you choose. Add or subtract with + and -.
Copy or download
Grab the converted list as text for your editor, spreadsheet, or subtitle file.
One timecode, every format
Video and subtitle work means juggling timecodes in different shapes: raw seconds for a script, HH:MM:SS for an editor, comma-milliseconds for SubRip (SRT), dot-milliseconds for WebVTT, and frame-based SMPTE timecode for an NLE. This converter takes any of them and shows all the others side by side, so you stop doing the math by hand.
Formats it understands
- Seconds — 90 or 90.5
- MM:SS — 1:30
- HH:MM:SS — 00:01:30
- SRT — 00:01:30,500 (comma milliseconds)
- VTT — 00:01:30.500 (dot milliseconds)
- SMPTE — 00:01:30:12, or 00:01:30;12 for drop-frame
Built for editors and subtitlers
Paste a whole column of timecodes and convert them in one pass — handy for spotting subtitle lists, building chapter markers, or matching cuts between tools that disagree on format. Every line shows SMPTE timecode at the frame rate you pick (23.976, 24, 25, 29.97 drop-frame or non-drop, 30, 50, 59.94 drop-frame or 60) and frame counts at 24, 25 and 30 fps. The rate starts at 25 and is remembered on your device. Everything runs locally, so even long lists stay private and fast.
What is SMPTE timecode, and why does 29.97 need drop-frame?
SMPTE timecode labels every video frame as hours, minutes, seconds and frames (HH:MM:SS:FF), the time and control code defined in the SMPTE ST 12-1 standard. NTSC-style video runs at 29.97 frames per second, which is 30 divided by 1.001, so a label that counts 30 frames to every second falls behind the clock; drop-frame timecode, as Wikipedia's SMPTE timecode article sets out, skips frame numbers 00 and 01 at the start of every minute except every tenth minute to keep the label on real time.
No pictures are thrown away, only numbers. Drop-frame is written with a semicolon before the frames (01:00:00;00) and non-drop with a colon (01:00:00:00). The converter refuses a drop-frame label that cannot exist, such as 00:01:00;00, rather than guessing what you meant.
| Frame rate | Timecode label | Real time | As an SRT timestamp |
|---|---|---|---|
| 25 fps | 01:00:00:00 | 3,600 seconds | 01:00:00,000 |
| 29.97 fps non-drop | 01:00:00:00 | 3,603.6 seconds | 01:00:03,600 |
| 29.97 fps drop-frame | 01:00:00;00 | 3,599.996 seconds | 00:59:59,996 |
| 23.976 fps | 01:00:00:00 | 3,603.6 seconds | 01:00:03,600 |
How SMPTE relates to SRT and WebVTT
Subtitle files do not count frames. The Library of Congress format description gives the SubRip timecode as hours:minutes:seconds,milliseconds with a comma (00:00:00,000), and the W3C WebVTT specification uses a full stop followed by three digits of thousandths, with the hours optional. Turning frame-based timecode into either one means dividing the frame count by the real frame rate. That is where the 3.6 seconds per hour in the table come from when 29.97 material is treated as an even 30.
Calculator mode
Put + or - between timecodes on one line, with a space on each side, to add or subtract them. The sum is worked out in whole frames at the chosen rate, so drop-frame arithmetic stays exact: at 29.97 drop-frame, 00:10:00;00 + 00:00:12;15 gives 00:10:12;15, which is 00:10:12,512 in SRT. Seconds and SRT timestamps can be mixed into a sum; they are rounded to the nearest frame first.
Answers
Frequently Asked Questions
What timecode formats are supported?
Seconds (90 or 90.5), MM:SS, HH:MM:SS, SRT timestamps with comma milliseconds, VTT timestamps with dot milliseconds, and SMPTE timecode HH:MM:SS:FF, with a semicolon for drop-frame. You can mix formats line by line.
Does it convert frames?
Yes. Each line is shown as SMPTE timecode at the frame rate you choose, from 23.976 to 60 fps including 29.97 and 59.94 drop-frame, and as frame counts at 24, 25 and 30 frames per second.
Can I convert many timecodes at once?
Yes. Put one timecode per line and every line is converted at the same time. You can copy or download the full result.
What is the difference between SRT and VTT timestamps?
They are the same time, written differently: SRT uses a comma before milliseconds (00:01:30,500) and WebVTT uses a dot (00:01:30.500).
What is drop-frame timecode?
Drop-frame is how SMPTE timecode stays on real time at 29.97 frames per second: it skips frame numbers 00 and 01 at the start of every minute except every tenth minute. No video frames are removed, only labels. Without it, an hour of 29.97 timecode runs 3.6 seconds behind the clock.
Can I add or subtract timecodes?
Yes. Write the timecodes on one line with a spaced plus or minus between them, for example 00:10:00:00 + 00:00:12:15. The result is calculated in frames at the selected rate and shown as SMPTE timecode, as an SRT timestamp and as a frame count.
Is my data uploaded?
No. All conversion happens in your browser. Nothing is sent to a server or stored.
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