Timelapse Calculator — interval and frame counts

Planning a timelapse is a balancing act between how long the real‑world scene lasts and how long you want the final video to be. This timelapse calculator helps you choose a shooting interval by turning those two goals into concrete numbers: how many photos you need, how often to capture each frame, and the buffer you should leave for your camera to write files reliably.

A timelapse video is just a sequence of still images played back quickly. The frame rate (FPS) tells you how many images are shown each second, while the interval tells you how often you take each photo. If you shoot a 2‑hour sunset and want a 20‑second clip at 24 FPS, you need 480 frames total. Divide the scene duration by the frame count, and you get the interval. The calculator does that math instantly so you can focus on the creative side of the shoot.

Step-by-step

1. Enter how long the real‑world scene will last (minutes or hours).
2. Choose your target clip length and frame rate.
3. Review the suggested interval and total frames needed.
4. Check the buffer note to ensure your camera can keep up.
5. Adjust the interval if you want slower or faster motion.

Real‑world use cases include capturing cloud movement, construction progress, traffic flow, star trails, or a busy city street. For fast‑moving subjects like crowds or traffic, you might use a shorter interval such as 1–3 seconds. For slow changes like plant growth or interior renovations, longer intervals like 30 seconds to several minutes can work well. The calculator helps you compare these options quickly.

Frame rate affects the feel of the final timelapse. Many creators choose 24 FPS for a cinematic look, 30 FPS for general web playback, and 60 FPS for ultra‑smooth motion. If your camera or memory card struggles, increase the interval slightly or reduce the frame rate so you avoid dropped frames and overheating.

For a natural motion blur, aim for a shutter speed roughly half your interval (the 180‑degree rule). This often requires an ND filter in daylight to keep exposures long enough without overexposing. It is a simple trick that makes timelapses feel smoother and more film‑like.

Tip: Match shutter to roughly half the interval (180 degree rule) for natural blur, especially with ND filters outdoors.

This calculator removes guesswork before you set up. Enter the scene duration, final clip length, and playback FPS to see the required interval, total frames, and slack time from rounding. The math is simple: total frames = length x FPS, interval = scene duration / total frames.

It runs entirely in your browser so you can use it offline on location. The warning callout flags sub-second intervals that may outrun camera buffers or SD cards. Use the output to pick ND strength and shutter times that keep a natural blur while staying within your camera’s limits.

Test your plan by firing a short burst at the chosen interval and reviewing buffer clearance. If shooting sunrise or sunset, start with this interval and adjust gradually as light changes to prevent flicker.