Timecode calculator

How to use the timecode calculator

1. 01Choose the frame rate your footage was shot or edited at.
2. 02Enter two timecodes in HH:MM:SS:FF format (use a semicolon before the frames on drop-frame rates, or let the calculator read either).
3. 03Choose add, subtract or convert to frames and seconds.
4. 04Read off the result: the timecode, the total frame count and the real elapsed seconds.

Drop-frame vs non-drop-frame timecode

Non-drop timecode counts frames the way the label suggests: at 25 fps, frame 24 rolls over to the next second, and there are always 25 frames in a second of timecode. That works cleanly whenever the frame rate is a whole number, which is why 24, 25, 30, 50 and 60 fps timecode is always non-drop.

29.97 fps and 59.94 fps are not whole numbers: they run at 30000/1001 and 60000/1001 frames per second, about 0.1% slower than 30 and 60. Non-drop timecode counts every frame as if the rate were exactly 30 or 60, so it falls behind a wall clock as recording goes on: after one real hour, non-drop 29.97 timecode reads roughly 00:59:56, about 3.6 seconds behind. Drop-frame timecode fixes this by skipping certain frame labels (never a real frame of video) so the timecode display keeps pace with real time. Non-drop 29.97 and 59.94 timecode still exists and is common in file-based workflows: it is simpler to do arithmetic on, but its label drifts from the clock over a long enough duration.

Which one a project uses is usually set by the broadcast standard or the camera, not by choice on an individual clip: a drop-frame master needs drop-frame timecode throughout, and mixing the two on the same timeline is a common source of off-by-a-few-frames errors when clips are conformed.

Converting timecode to frames and seconds

A frame count is timecode with the formatting stripped out: multiply the hours, minutes and seconds by the frame rate, add the frame field, and (for drop-frame) subtract the labels that were skipped along the way. It is the form you need for any arithmetic a spreadsheet or a script has to do, because HH:MM:SS:FF is not a number a calculator can add directly.

Real seconds are a second conversion on top of the frame count, and the one place people get 29.97 and 59.94 wrong: converting a frame count to real seconds must divide by the true rate (30000/1001, not 30) to match a stopwatch. Divide by the nominal rate instead and the result comes out about 0.1% short, understating how long the frames actually run for.

Which frame rate should I choose?

Match whatever the source footage or the delivery spec already says, rather than guessing from the platform. If you are working from a camera's metadata or an edit's project settings, that number is the one to use here: this calculator does not convert between frame rates, only timecode arithmetic and formatting at a single, fixed rate.

23.976 and 29.97 non-drop are the common cinema and US broadcast rates for file-based delivery; 25 and 50 are the PAL equivalents used across most of Europe; 29.97 and 59.94 drop-frame are what US broadcast timecode uses on air. If a spec sheet just says "30 fps" without qualifying drop or non-drop, it is worth confirming before you calculate a hard-out point, since the two give different answers.

How the numbers are worked out

Drop-frame timecode skips frame labels 00 and 01 at the start of every minute, except every tenth minute (00, 10, 20, 30, 40, 50), where nothing is skipped. At 59.94 fps drop-frame, four labels are skipped instead of two: 00 to 03. No video frame is ever discarded: only the label jumps forward, which is what keeps a drop-frame timecode display in step with a wall clock over a long recording.

Real seconds are calculated from the true frame rate, not the nominal one: 30000/1001 frames per second for 29.97, 60000/1001 for 59.94. That is roughly 29.97 and 59.94, but using the rounded figure compounds into a noticeable error over a long duration, so this calculator always divides by the exact fraction.

Questions about the timecode calculator

What is drop-frame timecode?

It is a labelling scheme for 29.97 and 59.94 fps timecode that periodically skips frame labels so the displayed time tracks a wall clock. No video frames are removed, only certain timecode numbers are never used, which is why formatted drop-frame timecode uses a semicolon before the frames (00:01:00;02) instead of a colon.

Why does 29.97 fps need drop-frame?

29.97 fps actually runs at 30000/1001 frames per second, about 0.1% slower than a clean 30. Counted as if it were 30, non-drop timecode falls behind real time as it runs: after a real hour has passed, it reads roughly 00:59:56, about 3.6 seconds behind. Drop-frame timecode corrects for that drift by skipping frame labels at set points, so long-form and live broadcast timing stays accurate against the clock.

How many frames are in an hour at 25 fps?

90,000 frames: 25 fps is a whole number, so one hour of non-drop timecode is simply 3,600 seconds multiplied by 25 frames per second, with no drop-frame correction needed.

Does this calculator work for 23.976 footage?

Yes. Pick 23.976 fps from the frame rate list and enter timecode as normal; 23.976 is always non-drop, so the arithmetic is the same as any other whole-number rate, with real seconds calculated from the true 24000/1001 rate.

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Updated 22 September 2026 · All free tools