Add and subtract SMPTE timecodes, measure the duration between In and Out points, and convert between timecode, frames and seconds at 23.976, 24, 25, 29.97 drop-frame and non-drop, 30, 50, 59.94 and 60 fps. Drop-frame math and invalid drop-frame timecodes are handled correctly.
Last updated:
Calculation
HH:MM:SS:FF (or MM:SS:FF); ; or . separators are fine. You can also add frames (48f) or seconds (2.5s).
s
Enter your values to see the result.
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How to use the Timecode Calculator
Pick the calculation: add/subtract, duration, or one of the conversions.
Choose the frame rate of your project or timeline.
Enter timecodes as HH:MM:SS:FF, one per line, using + or − to add or subtract.
Read the result in timecode, frames and real time.
Check the table for the same duration at other frame rates.
Drop-frame (29.97 / 59.94): frames = (HH × 3600 + MM × 60 + SS) × nominal + FF − d × (total minutes − ⌊total minutes ÷ 10⌋), where nominal is 30 or 60, d = 2 or 4 and total minutes = 60 × HH + MM.
Real time = frames ÷ actual fps (for example 30000 ÷ 1001 = 29.97003 fps).
Example: 01:00:00;00 at 29.97 DF = 3,600 × 30 − 2 × (60 − 6) = 108,000 − 108 = 107,892 frames, and 107,892 ÷ 29.97003 = 3,599.996 s, which is within 4 ms of one hour.
Frame rate reference
Rate
Exact fps
Frames per TC hour
Real length of 1 TC hour
Typical use
23.976
24000/1001
86,400
1:00:03.6
Film-style video for NTSC regions, streaming
24
24
86,400
1:00:00
Cinema, DCP
25
25
90,000
1:00:00
PAL broadcast, Europe
29.97 DF
30000/1001
107,892
1:00:00.0
NTSC broadcast (US TV)
29.97 NDF
30000/1001
108,000
1:00:03.6
Editing, some broadcast workflows
30
30
108,000
1:00:00
Web, screen recordings
50
50
180,000
1:00:00
PAL high frame rate
59.94 DF
60000/1001
215,784
1:00:00.0
NTSC high frame rate broadcast
60
60
216,000
1:00:00
Gaming, web, sports
Tips
Match the project rate: timecode is only meaningful with its frame rate; 00:00:01:12 is 36 frames at 24 fps but 42 frames at 30 fps.
Hour 01 starts: many broadcast masters start programme at 01:00:00:00 (often with bars and tone before), which avoids negative timecode in pre-roll.
Converting between rates: use the "same real duration" column to keep lengths in sync, or the "same frame count" column when frames are re-timed (for example 24 → 23.976 slow-down).
Frequently asked questions
How do I convert timecode to frames?
Multiply the hours by 3,600, the minutes by 60, add the seconds, multiply by the frame rate and add the frames. At 24 fps, 00:10:00:00 is 600 s × 24 = 14,400 frames. Drop-frame timecode also subtracts the skipped frame numbers.
What is drop-frame timecode?
At 29.97 fps, counting 30 frames per second would drift 3.6 seconds per hour behind the clock. Drop-frame timecode skips frame numbers 00 and 01 at the start of every minute except every tenth minute (00, 10, 20…), so the timecode stays in step with real time. No actual frames are dropped; only labels are skipped. At 59.94 fps, four numbers are skipped.
How is drop-frame written?
Drop-frame timecode is usually written with a semicolon before the frames, such as 01:00:00;00, while non-drop uses colons throughout (01:00:00:00). This calculator accepts either and writes drop-frame with a semicolon.
Should duration include the out frame?
Most editing software treats the Out point as exclusive: a clip from 01:00:00:00 to 01:00:01:00 lasts exactly one second (24 frames at 24 fps). Some workflows mark the last frame itself as the Out point; tick 'Include the out frame' to add one frame in that case.
Why does 23.976 timecode not match the clock?
23.976 fps has no drop-frame standard, so its timecode counts 24 frames per timecode second while real playback runs 0.1% slower. One hour of 23.976 timecode lasts 1 hour 3.6 seconds of real time. The calculator shows both values.
How many frames are in an hour?
At 24 fps 86,400, at 25 fps 90,000, at 30 fps 108,000 and at 60 fps 216,000. With 29.97 drop-frame, one hour of timecode (01:00:00;00) is 107,892 frames.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.