SUBTITLE REFERENCE DESK
Frames and timecode calculator
Convert frame counts to elapsed time, or find the nearest frame at an exact fractional frame rate.
How it works
Elapsed milliseconds = frames × 1000 ÷ frames per second. The reverse conversion rounds to the nearest whole frame. Fractional rates use exact ratios, such as 30000/1001, rather than the rounded label 29.97.
Worked example
250 frames at 25 fps = 10 seconds. At 30000/1001 fps, 300 frames = 10.010 seconds. To retime subtitles from 24 fps to 25 fps, multiply cue times by 24/25: 10 seconds becomes 9.600 seconds.
Useful limits
This tool calculates elapsed time. It does not implement SMPTE drop-frame numbering. Choose Sync in the editor to preview and apply frame-rate changes to your captions.
FFmpeg video-rate notation · Reviewed 2026-10-04 · Licenses