Timecode Calculator
What is SMPTE Timecode?
In video editing, accuracy is everything. You cannot just say "about 5 minutes in." You need to know the exact frame. SMPTE Timecode is the global standard for labeling individual frames of video.
The format is HH:MM:SS:FF (Hours : Minutes : Seconds : Frames).
- Hours: 00-23
- Minutes: 00-59
- Seconds: 00-59
- Frames: 00 to (Frame Rate - 1)
The Mystery of 29.97 (Why does it exist?)
Why do we have weird frame rates like 23.976 and 29.97? It's because of Color TV.
In the 1950s, Black & White TV ran at exactly 30 fps. When engineers added color information to the signal, it interfered with the audio. To fix this without breaking existing TVs, they slowed the video down by exactly 0.1%.
30 fps became 29.97 fps. 24 fps became 23.976 fps.
Drop Frame (DF) vs. Non-Drop Frame (NDF)
This 0.1% slowdown created a math problem. If you count 29.97 frames as "30", your timecode clock will drift away from real time.
- Non-Drop Frame (NDF): The clock assumes 30 fps. After 1 hour of real time, the timecode will show 01:00:03:18. It is inaccurate for broadcast timing.
- Drop Frame (DF): To fix the drift, we "Drop" (skip) frame numbers. We don't delete actual video frames; we just skip the labels.
In Drop Frame mode, the first two frame numbers (00 and 01) are skipped at the start of every minute, except for every 10th minute (00, 10, 20, etc.). This mathematical trick keeps the timecode synced perfectly with a wall clock.
Frame Rate Cheat Sheet
| Frame Rate | Standard | Usage |
|---|---|---|
| 23.976 | NTSC Film | Standard for Movies, TV Shows, YouTube. |
| 24.00 | True Cinema | Theatrical projections. |
| 25.00 | PAL | TV Standard in Europe, Australia, Asia. |
| 29.97 | NTSC Video | Broadcast TV News, Sports in US/Japan. |
| 60.00 | High Rate | Video Games, Slow Motion footage. |
Semicolons vs. Colons
How do you know if a file is Drop Frame or not? Look at the punctuation.
- 01:00:00:00 (Colons) = Non-Drop Frame (NDF).
- 01:00:00;00 (Semicolons) = Drop Frame (DF).