Time-Lapse Calculator (Interval · Frames · Clip Length)
Event duration, shooting interval and playback fps solved into frames, clip length and storage — with interval presets for clouds, stars, crowds and construction.
The speed-up factor (interval × fps) is the director's number: 120× turns an hour into 30 seconds. Rookie mistake: intervals too long for the subject — clouds at 30 s strobe instead of flow. When in doubt shoot a shorter interval; you can always drop frames later, never add them.
Formula
⚠️ Optical estimates based on standard formulas and circle-of-confusion conventions — lens markings, sensor specs and real-world testing have the final word.
Event duration, shooting interval and playback fps solved into frames, clip length and storage — with interval presets for clouds, stars, crowds and construction.
About Time-Lapse Calculator (Interval · Frames · Clip Length)
Time-lapse is arithmetic wearing an artist's beret: event duration divided by interval gives frames, frames divided by playback rate gives clip length, and their ratio — interval times fps — is how many times faster the world will appear to run. This calculator solves the whole chain in one pass, adds the storage bill (the line item that ends shoots early), and carries the interval presets that separate flowing clouds from strobing ones.
How to use Time-Lapse Calculator (Interval · Frames · Clip Length)
- 1Enter — sensible defaults are pre-filled so you see a worked result immediately.
- 2Read the live results: .
- 3Check the "With your numbers" line to see the formula frames = duration ÷ interval; clip = frames ÷ fps; speed-up factor = interval × fps substituted step by step.
- 4Adjust inputs (or flip the unit toggle) until the scenario matches yours, then copy or share the result.
Why use Time-Lapse Calculator (Interval · Frames · Clip Length)?
- ✓Instant, free and private — every calculation runs in your browser, nothing is uploaded
- ✓Built on the published formula frames = duration ÷ interval; clip = frames ÷ fps; speed-up factor = interval × fps with sources cited on the page
- ✓The speed-up factor (interval × fps) is the director's number: 120× turns an hour into 30 seconds. Rookie mistake: intervals too long for the subject — clouds at 30 s strobe instead of flow. When in doubt shoot a shorter interval; you can always drop frames later, never add them.
- ✓Switch units, tweak any input and watch every result update live
Frequently asked questions
What interval should I use for which subject?+
Match the interval to the subject's motion scale: fast clouds and busy crowds 2–5 s; ordinary clouds and sunsets 5–10 s; shadows crawling across a landscape 15–30 s; stars 20–40 s (bounded by the exposure itself — see our 500-rule tool); flowers opening 5–15 min; construction sites 15 min–several hours across months. The test: between consecutive frames, the subject should move a small, similar amount — large jumps read as strobing, which is the signature of an interval chosen for storage instead of motion.
How long a clip do I actually need?+
Brutally less than shooters assume: in finished edits, a time-lapse scene holds 5–15 seconds before the viewer's eye wants the next shot — a 10-second clip at 24 fps is just 240 frames, an hour of shooting at 15-second intervals. Plan from the edit backward: decide the clip length, multiply by fps for frames, multiply by interval for shooting time. The classic error runs the math forward from 'I'll shoot all afternoon' and delivers four minutes of footage no edit will ever use.
Should I shoot RAW for time-lapse, given the storage cost?+
For anything with changing light (sunsets, day-to-night 'holy grail' transitions) — yes: RAW's latitude lets you ramp exposure smoothly in post and rescue the highlights a JPEG bakes in. For stable mid-day light, high-quality JPEG halves the storage and quadruples buffer headroom. The numbers this tool computes decide for you: 1,800 frames × 45 MB is 79 GB per hour — one sunset fills a card. Common compromise: RAW for transitions, JPEG for the long boring middles, merged in the edit.
What's shutter angle / the 180° rule in time-lapse?+
Cinema's motion-blur convention imported: expose each frame for about half the interval (a 6-s interval → ~3-s exposure, often via ND filters in daylight) and moving elements blur into silky continuity instead of staccato sharpness. It's an aesthetic, not a law — sharp short exposures give the energetic 'hyperlapse' look; long 'dragged' shutters smooth traffic into light rivers. What ruins clips is flicker from auto-exposure hunting between frames: lock everything manual, including white balance and aperture (or use lens-twist de-clicking tricks for aperture flicker).
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