SMPTE timecode in, SMPTE timecode out — frame-accurate math at 24 and 30 fps, mixed freely with plain durations.
Timecode math is base-60 with a frame twist: frames roll over at the frame rate, not at 60. One wrong carry and your EDL is off. TCalc parses HH:MM:SS:FF natively — write the frame rate as a suffix (f24, f30) and every operation stays frame-accurate.
The Film layout below has timecode keys ready; results format back as SMPTE, or as plain time when that reads better.
Add a clip to a sequence — carry across seconds, minutes, and the hour.
Runtime between two program marks.
Exactly one frame at 30 fps — the borrow is correct.
Split two hours of footage into three equal review blocks.
Add field by field from the right, carrying frames at the frame rate and seconds/minutes at 60. At 24 fps, 00:59:30:00 + 00:01:15:12 = 01:00:45:12. In TCalc you type both values with an f24 suffix and the carry is handled.
Output formats include 24 fps and 30 fps timecode plus a configurable default frame rate; input takes an explicit per-value suffix like f24 or f30.
Yes — timecode is a duration under the hood. Add a 90-minute runtime to a timecode and format the result back as SMPTE at your frame rate.