Frame Rate & Timecode Converter
Timecode ↔ frames ↔ seconds at 23.976 to 60 fps with drop-frame (SMPTE) counting, the drift of non-drop labels and the same duration at another rate.
The frame count, the timecode label (drop or non-drop), the real duration as a clock time, the drift between label and clock, and the equivalent frames at a second rate — exact integer arithmetic.
Example: 01:00:00;00 drop-frame at 29.97 fps is 107,892 frames = 3599.996 s; the same frames in non-drop read 00:59:56:12. At 25 fps 90.5 s is 2,262.5 frames — rounded to 2,263, 00:01:30:13.
A frame label,
not a clock.
What timecode counts, why drop-frame exists, and what the conversion does and does not do.
Frames and labels
HH:MM:SS:FF counts frames at the nominal rate: frames = ((H·60 + M)·60 + S) × N + F, with N = 24, 25, 30, 48, 50 or 60. The real duration is frames ÷ the exact rate — and for 23.976, 29.97 and 59.94 the exact rate is 24000/1001, 30000/1001 and 60000/1001, so a label that reads one hour has 3.6 s more real time behind it than it says.
Drop-frame
SMPTE ST 12-1 fixes that for 29.97 and 59.94 by skipping frame numbers 00 and 01 (00–03 at 59.94) at the start of every minute except minutes 00, 10, 20, 30, 40 and 50 — 18 (36) numbers per ten minutes, exactly the difference between 30 and 29.97 frames per second over that span. No pictures are dropped; the labels simply jump, so 01:00:00;00 is 107,892 frames and lands within a few frames of a real hour. A label that names a skipped number is refused.
Other rates
The "also at" option gives the frame count of the same real duration at another rate, rounded to a whole frame; it is arithmetic, not a frame-rate conversion — pulldown, retiming and audio pitch are editorial decisions. 23.976 has no drop-frame form, so its labels always run 0.1 % behind the clock. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- SMPTE ST 12-1 time and control code: HH:MM:SS:FF at the nominal rate; drop-frame skips frame numbers 0–1 (0–3 at 59.94) each minute except every tenth; fractional rates N × 1000/1001
Last reviewed 21 September 2026. How results are checked: How we verify.