Timecode calculator
Add, subtract, and convert SMPTE timecode.
Work timecode against frames and real time, add and subtract two timecodes, and switch frame rate, including drop-frame at 29.97 and 59.94. Set a programme start timecode: 01:00:00:00 (1-hour), 10:00:00:00 (the UK 10-hour convention), or any custom start. The frame and elapsed-time readouts measure from it.
Convert
Edit any field. The others follow.
0.000s at 25
Add & subtract
How timecode maths works
SMPTE timecode labels each frame as HH:MM:SS:FF. To add or subtract two timecodes you convert each to an absolute frame count, do the arithmetic, then convert back, which is exactly what this tool does, so the result is frame-accurate at your chosen rate.
Drop-frame vs non-drop
The 29.97 and 59.94 fps rates run slightly slower than 30 and 60, so counting every frame steadily lags the clock: after an hour the timecode reads about 3.6 s short of real elapsed time. Drop-frame timecode skips two frame numbers (four at 59.94) at the top of every minute except minutes 00, 10, 20, 30, 40 and 50, closing that gap so the count tracks wall-clock. No actual frames are dropped, only labels. Drop-frame is written with a semicolon, HH:MM:SS;FF. PAL rates (25, 50) and the whole-number rates (24, 30, 60) never use drop-frame.
Delivering to a broadcast or streaming spec? See what SpectraQC checks, including timecode continuity and start-of-programme timecode.