Free Shutter Angle Calculator
Shutter angle expresses shutter speed as a fraction of the frame interval, with 360° being one full frame. In video, shutter speed is described as an angle. The cinematic standard — the 180° rule — sets the shutter to 1/(2 × frame rate): 1/48 s at 24 fps, 1/60 s at 30 fps, 1/120 s at 60 fps. That's the natural motion blur your eye expects.
Angle → speed
Result
Common frame rate × angle table
| FPS | 360° | 270° | 180° | 90° | 45° |
|---|---|---|---|---|---|
| 24 | 1/24 s | 1/32 s | 1/48 s | 1/96 s | 1/192 s |
| 25 | 1/25 s | 1/33 s | 1/50 s | 1/100 s | 1/200 s |
| 30 | 1/30 s | 1/40 s | 1/60 s | 1/120 s | 1/240 s |
| 50 | 1/50 s | 1/67 s | 1/100 s | 1/200 s | 1/400 s |
| 60 | 1/60 s | 1/80 s | 1/120 s | 1/240 s | 1/480 s |
| 120 | 1/120 s | 1/160 s | 1/240 s | 1/480 s | 1/960 s |
Worked example
You're shooting 24 fps and want the standard cinematic look: enter 180°, and the calculator returns 1/48 s — the classic rule (shutter = 1/(2×fps)). Switch to 60 fps for slow motion and it becomes 1/120 s. Now the creative choices: 360° (1/24 s) adds motion blur for dreamy pans, while 90° (1/96 s) makes action crisper and more staccato. Videographers memorize 180° because it sits at the sweet spot — enough blur for smooth motion, enough edge for detail. The calculator removes the mental math when you're juggling frame rates, resolutions and ND filters on set.
Related tools & guides
Video ND Filter Calculator
ND stops to hold the 180° shutter in daylight.
Open →Exposure Calculator
Aperture, shutter, ISO and EV conversions.
Open →Shutter Speed Chart
When to use which shutter speed.
Open →Shutter angle FAQ
Why 180 degrees?
Shutter angle describes how long the shutter stays open per frame, as a fraction of a full rotation. At 180° it's open half the frame time, giving motion blur that matches how the eye tracks movement — too open (360°) blurs, too closed (45°) stutters.
What shutter speed for slow motion?
Same rule: 1/(2 × fps). At 120 fps that's 1/240 s. Many cameras auto-set this when you select 180° in video mode — check your menu.
Does the 180° rule apply to stills?
No — stills use shutter speed directly (1/focal length or faster for handheld). The angle system is a video/cinema convention, though the motion-blur logic is the same.