SMPTE Timecode Utility

SMPTE Timecode Decoder

Decode SMPTE-style timecode into hours, minutes, seconds and frames, calculate the absolute frame number, detect drop-frame notation, estimate elapsed time and inspect frame-rate details.

✓ HH:MM:SS:FF ✓ Drop-Frame ✓ Frame Number ✓ 23.976 / 24 ✓ 25 / 30 ✓ 29.97 / 59.94

SMPTE Timecode Decode

● Ready

SMPTE Timecode Use a colon before frames for non-drop timecode and a semicolon for drop-frame notation, for example 01:00:00;00.

Frame Rate

Drop-Frame Mode Drop-frame calculation is supported for 29.97 and 59.94 fps.

Hour Validation

Drop-frame reminder: drop-frame timecode does not remove video frames. It skips selected timecode numbers so the displayed timecode stays closer to real clock time at 29.97 or 59.94 fps.

SMPTE Timecode Result Decoded

Absolute Frame Number —

Hours —

Minutes —

Seconds —

Frames —

Frame Rate —

Nominal FPS —

Drop-Frame —

Total Frames —

Elapsed Seconds —

Elapsed Time —

Dropped Numbers —

Status —

Calculation Breakdown —

Drop-Frame Analysis —

Validation & Notes —

What Is SMPTE Timecode?

SMPTE timecode is a frame-based time labeling system used in film, television, broadcast, audio and video production. A common representation contains hours, minutes, seconds and frame numbers.

HH:MM:SS:FF

Example:

01:23:45:12

01 = Hours
23 = Minutes
45 = Seconds
12 = Frames

SMPTE Timecode to Frame Number

For non-drop timecode, the conversion uses the nominal integer frame rate.

Total Frames =

Hours × 3600 × FPS
+
Minutes × 60 × FPS
+
Seconds × FPS
+
Frames

Example at 24 fps

Timecode:

00:01:00:00

Frame Rate:
24 fps

Total Frames:

0 × 3600 × 24
+
1 × 60 × 24

= 1440 frames

What Is Drop-Frame Timecode?

Drop-frame timecode is used with fractional NTSC-related rates such as 29.97 fps and 59.94 fps. The purpose is to reduce the difference between timecode labels and elapsed clock time.

No actual video frames are discarded. Instead, certain frame numbers are omitted from the timecode count.

29.97 Drop-Frame Rule

At 29.97 fps drop-frame timecode, frame numbers 00 and 01 are skipped at the start of each minute except every tenth minute.

Skipped at:

00:01:00;00
00:01:00;01

00:02:00;00
00:02:00;01

...

But not at:

00:10:00;00

59.94 Drop-Frame Rule

At 59.94 fps, four frame numbers are skipped at the start of applicable minutes rather than two.

Skipped numbers:

00
01
02
03

at each minute except every tenth minute.

Drop-Frame Formula

Nominal Frames =
((Hours × 3600)
+ (Minutes × 60)
+ Seconds)
× Nominal FPS
+ Frames

Dropped Frame Numbers =
Drop Count
×
(Total Minutes − floor(Total Minutes / 10))

Actual Frame Number =
Nominal Frames − Dropped Frame Numbers

29.97 fps vs 30 fps

Rate	Actual FPS	Nominal Count	Drop-Frame Possible
29.97	30000/1001	30	Yes
30	30	30	No
59.94	60000/1001	60	Yes
60	60	60	No

Colon vs Semicolon Timecode

A colon is commonly used to display non-drop frame timecode, while a semicolon before the frame field is commonly used to identify drop-frame timecode.

Non-Drop:

01:00:00:00

Drop-Frame:

01:00:00;00

Timecode Frame Range

The frame field must remain below the nominal integer frame count for the selected frame rate.

24 fps:
Frames 00–23

25 fps:
Frames 00–24

29.97 / 30 fps:
Frames 00–29

50 fps:
Frames 00–49

59.94 / 60 fps:
Frames 00–59

SMPTE Timecode Decoder FAQs

What does SMPTE timecode look like?

A common form is HH:MM:SS:FF, representing hours, minutes, seconds and frames.

What does a semicolon in timecode mean?

It commonly indicates drop-frame notation, such as 01:00:00;00.

Does drop-frame timecode remove video frames?

No. It skips selected timecode numbers, not actual captured or displayed video frames.

How many frame numbers are dropped at 29.97 fps?

Two timecode frame numbers are skipped at the start of each minute except every tenth minute.

How many are skipped at 59.94 fps?

Four timecode frame numbers are skipped at applicable minute boundaries.

Can 24 fps use drop-frame timecode?

Not with the standard 29.97/59.94 drop-frame scheme implemented by this calculator.

What is the maximum frame field at 24 fps?

The frame field ranges from 00 through 23.

Does this tool decode LTC audio waveforms?

No. This tool decodes textual SMPTE timecode values and frame-number calculations, not raw LTC waveform data.