Time-Lapse Interval Calculator: Shots and Clip Length

How to use it

Type the Event length and choose hours or minutes in Event length unit.
Type the Clip length (seconds) of the finished video and the Frame rate (frames per second).
Read the Interval between shots (seconds), the exact time from one shot to the next.
Set the Interval to set (whole seconds) on the camera, and check the Clip length at the whole-second interval you will get.
Use the table to compare other clip lengths for the same event.

How the interval is calculated

The frames a clip needs are its length multiplied by the frame rate, rounded to whole frames. A 10 second clip at 25 frames per second needs 250 frames.

The camera spreads those frames over the event with an interval of the event length divided by the frames minus one. The Nikon Z30 manual counts a time-lapse the same way: the shooting time divided by the interval, rounded up, plus one gives the number of frames.

frames = clip length × frame rate
interval = event length ÷ (frames − 1)
frames at a set interval = event length ÷ interval, rounded up, plus one

Whole-second intervals

The OM System OM-1 Mark II sets the interval in whole seconds, from 00:00:01 to 24:00:00. The calculator rounds the exact interval down to a whole second, so the camera takes at least the frames the clip needs and the whole event is covered. The clip is then a little longer than planned, and the result shows its length.

When the exact interval is under one second, no whole-second setting exists, and the calculator reports that instead of a result.

What the calculator does not cover

Changes of light during the event. The exposure value calculator helps with the settings for one moment.
The limits of your camera, such as the maximum length of a time-lapse video, which the Nikon Z30 manual gives as 20 minutes.
The frame rates your camera offers: the OM-1 Mark II offers 30, 15, 10 and 5 fps for time-lapse movies, so use a rate your camera lists.

Worked example: a 2-hour event as a 10-second clip at 25 fps

The clip needs 10 × 25 = 250 frames. The exact interval is 7,200 ÷ 249 = 28.92 seconds. Set 28 seconds on the camera: the event then gives 259 frames, a clip of 10.4 seconds.

Clip length	Shots	Interval (s)
5 s	125	58.06
10 s	250	28.92
15 s	375	19.25
20 s	500	14.43
30 s	750	9.61
60 s	1,500	4.80

Frequently asked questions

Why is the interval not the event length divided by the clip frames?

The count follows the camera: the Nikon manual gives the frames as the shooting time divided by the interval, rounded up, plus one. With the interval set this way, the first frame starts the sequence and the last frame ends the event.

Why does the clip come out longer than my clip length?

The camera takes whole-second intervals, and the calculator rounds the exact interval down. The camera then takes slightly more frames than the exact interval would, so the clip is a little longer. The clip length at the whole-second interval shows the result.

Can I use an interval under one second?

Not with this calculator: when the exact interval is under one second, it reports an error. The OM System OM-1 Mark II sets intervals from one second, so a clip with more frames than the event allows needs a longer event, a shorter clip or a lower frame rate.

Which frame rate should I choose?

Choose the frame rate of the clip you want to make, and one that your camera's time-lapse setting offers. A lower frame rate needs fewer frames for the same clip length, so the interval between shots gets longer.

Does the calculator handle events longer than a day?

Yes: the event length can be typed in hours or minutes. Check that the interval stays within your camera's range; the OM-1 Mark II's interval goes up to 24 hours.

Sources

Figures and text last checked on Thursday, November 12, 2026.

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