Time-Lapse Clip Length Calculator
A time-lapse compresses a long event into a short clip by capturing frames at a fixed interval and playing them at video speed. To plan one you need to balance three numbers: how long you shoot, the interval between frames, and the playback frame rate. This calculator returns the number of frames you will capture, the final clip length, and the total shooting time. Enter your shooting duration, interval, and playback frame rate.
Time-lapse formula
Frames = shooting seconds / interval seconds
Clip length = frames / frame rate
Compression = shooting seconds / clip length
The number of frames is how many shots fit into your shooting window. Dividing by the playback frame rate gives the clip length. The compression ratio shows how much real time is condensed into each second of video.
Worked example
Shooting for 60 minutes (3,600 seconds) at a 2 second interval gives 3,600 / 2 = 1,800 frames. At 30 fps the clip is 1,800 / 30 = 60.00 seconds. Compression = 3,600 / 60 = 60.00, so each second of video represents 60 seconds of real time.
Time-lapse: frequently asked questions
How do I calculate the length of a time-lapse clip?
Divide the number of frames you capture by the playback frame rate. The number of frames is the total shooting time divided by the interval between shots. For example, 1,800 frames played at 30 fps gives a 60 second clip.
How many photos do I need for a time-lapse?
Frames needed equals the shooting duration divided by the interval. To shoot for 1 hour (3,600 seconds) at a 2 second interval you capture 1,800 frames. At 30 fps that becomes a 60 second clip.
What interval should I use for a time-lapse?
Faster-moving subjects need shorter intervals: 1 to 2 seconds for clouds and traffic, 5 to 30 seconds for sunsets, and minutes for stars or construction. The interval, total duration, and frame rate together set how long and how smooth the final clip is.
Sources
- NIST: Time and Frequency Division (the second).
- Clip length = frames / frame rate is the definition of frame-based playback; no external figure is required.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.