Drop-Frame Timecode Calculator
Add and subtract SMPTE timecodes with correct drop-frame handling for 29.97 and 59.94 fps, and convert between timecode and frame counts.
About this tool
A precise SMPTE timecode calculator that implements true drop-frame conversion. Enter a starting timecode (tc1) or a frame count, an operation (add/sub), a second timecode (tc2), the frame rate and an optional drop=auto/true/false flag. It converts to a total frame count and back, performs the arithmetic, and returns the resulting timecode using the correct separator. Built for editors, colorists and broadcast engineers who need frame-accurate math.
Frequently asked questions
What is drop-frame timecode?
Drop-frame timecode skips two frame numbers (four at 59.94) at the start of each minute except every tenth minute so the displayed time stays in sync with real elapsed time at 29.97/59.94 fps. No actual frames are dropped.
Which separator marks drop-frame versus non-drop?
By convention a semicolon before the frames (01:00:00;00) denotes drop-frame and a colon (01:00:00:00) denotes non-drop. This calculator follows that convention in its output.
How do I add two timecodes?
Set op=add (or sub), give tc1 and tc2 in HH:MM:SS;FF form and the fps. You can also pass frames=N to work directly in frame counts.