How to use this calculator
Enter a shooting window and an interval measured from the start of one exposure to the start of the next. Choose the playback frame rate and your camera’s approximate file size per photo. Exposure must be shorter than the interval.
The formula
A worked example
A 60 minute window at a 10 second interval contains 360 frame starts, from 0 to 3,590 seconds. At 24 fps, the clip is 15 seconds. At 25 MB per image, the photos need about 9 GB.
Assumptions & limitations
Uses first-frame-at-zero and an end-exclusive window; camera implementations can differ. Frames are counted by exposure start, so the last exposure may end after the window. Exposure shorter than interval does not guarantee enough processing or write time.
Common questions
Does the interval include the exposure?
Yes. It is start-to-start. Leave time after each exposure for processing, writing, and camera behavior.
Why might my camera count a different number?
Some cameras include a frame at the ending time or round the number of intervals differently. Check your camera’s convention.
Supporting reference
The method above states this calculator’s assumptions. This reference provides related definitions and technical context.
Nikon: D850 time-lapse movie planning ↗Formula and worked example checked against automated test cases. About our methodology.