What it's for
A timelapse compresses a long event (a sunset, something being built, cloud movement) into a short video by taking a photo at a fixed interval. This calculator solves the two most common scenarios: finding the interval and number of shots needed for a video of a target duration, or finding how many shots and how many seconds of video a given shot interval will produce.
Formulas used
From video duration: the total shots needed is total_shots = video_duration_in_seconds × fps, and the interval between each shot is interval = event_duration_in_seconds / total_shots. In reverse, from a fixed interval: total_shots = event_duration_in_seconds / interval, and the resulting video duration is video_duration = total_shots / fps.
Worked example
A 2-hour sunset (7,200 seconds), compressed into a 10-second video at 24fps, needs 240 shots (10×24), taken every 30 seconds (7,200÷240).
Practical tips
Fast-moving events (clouds, traffic) typically use short intervals (1-5 seconds); slow events (construction, plant growth) use intervals of minutes to hours. Also check that your camera's battery and memory card can handle the total number of shots calculated before starting the capture.
Limitations
The calculation doesn't account for camera settling time between shots (relevant at very short intervals with slower cameras) nor storage space needed, since that varies a lot by camera and file format.
Frequently asked questions
What interval should I use for moving clouds?
It depends on how fast the clouds are moving, but intervals of 2 to 10 seconds usually work well for moderately moving clouds — test a small batch of shots before recording the full sequence.
Why does the video's fps matter so much?
Because it determines how many shots, in total, are needed to fill the target duration of the final video — a video at 30fps needs 25% more shots than the same video at 24fps for the same duration.
Does this calculator tell me how much storage I need?
No — required storage depends on the file format (RAW or JPEG) and the camera's resolution, which vary a lot between gear, so we don't include that estimate.