Timecode calculator
Add and subtract timecodes, measure an end-exclusive clip and convert frame rates. Explicit drop-frame and rounding rules.
Your calculation
00:01:00:00 + 00:00:30:00 = 00:01:30:00 2,250 frames · 90.000000 elapsed seconds
23.976, 29.97 and 59.94 use 24000/1001, 30000/1001 and 60000/1001 fps. A negative or 24-hour result stops rather than wrapping. This does not alter media.
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Download the free script templates, printable speaking-time table and editable CSV together. PDF, Word and Markdown for Notion import are included. No email needed; downloading does not subscribe you.
Time estimates help you plan narration; they do not measure recordings, generate a video or replace source review.
How to use it
- Enter your own input, or load the labelled example.
- Run the tool and review its complete result and limitations.
- Download the draft or report, then check it in your intended workflow.
What to check
Timecode labels are not subtitles. Rate conversion preserves elapsed time rounded to the nearest frame; it does not retime a video. Drop-frame skips labels, never pictures.
Examples and common questions
How do I add 30 seconds to a timecode?
At 25 fps NDF, 00:01:00:00 + 00:00:30:00 = 00:01:30:00, or 2,250 frames. Select your actual project rate before calculating.
What is drop-frame timecode?
Drop-frame timecode skips frame labels to keep 29.97 or 59.94 fps timecode close to clock time. It does not delete video frames. This tool uses a semicolon before the frame field for DF.
Does frame-rate conversion change my video?
No. It converts a frame position to elapsed time and rounds to the nearest whole frame at the target rate. The output is a target NDF label and a reported rounding difference. No media is processed.
Frame-label reference: Apple timecode technical note. Use the timecode glossary to compare labels with subtitle timestamps.
Continue: YouTube delivery
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Working on a specific brief? Request a sample to discuss scope and availability.
Keep your workflow moving
What would you like to do next?
A few useful next steps. Open a tool and bring your own file or text.
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Example preview
Local captions + optional local video
Edit → check → preview → export
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Estimate video file size from duration and video/audio bitrates, or calculate a video bitrate for a target size budget.
Example preview
10 min · 8 Mbps video + 128 kbps audio
609.6 MB estimated
Aspect ratio calculator for video, images & screens
Dimensions & aspect ratio
Reduce dimensions to an aspect ratio and estimate a matching height at a new width.
Example preview
1920 × 1080
16 : 9
Free deterministic tool · updated November 4, 2026.