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.
Shutter speed by frame rate and shutter angle
Short answer: the 180° shutter rule sets exposure time to half the frame interval, so 24 fps gives 1/48 s, 30 fps gives 1/60 s and 60 fps gives 1/120 s. Multiply the frame rate by 360 and divide by the shutter angle to get the exact speed: 24 × 360 / 180 = 48.
| Frame rate | 360° | 180° | 90° | 45° |
|---|---|---|---|---|
| 23.976 fps | 1/24 s | 1/48 s | 1/100 s | 1/200 s |
| 24 fps | 1/24 s | 1/48 s | 1/100 s | 1/200 s |
| 25 fps | 1/25 s | 1/50 s | 1/100 s | 1/200 s |
| 29.97 fps | 1/30 s | 1/59 s | 1/125 s | 1/250 s |
| 30 fps | 1/30 s | 1/59 s | 1/125 s | 1/250 s |
| 48 fps | 1/48 s | 1/100 s | 1/200 s | 1/333 s |
| 50 fps | 1/50 s | 1/100 s | 1/200 s | 1/333 s |
| 59.94 fps | 1/59 s | 1/125 s | 1/250 s | 1/500 s |
| 60 fps | 1/59 s | 1/125 s | 1/250 s | 1/500 s |
| 120 fps | 1/125 s | 1/250 s | 1/500 s | 1/1000 s |
| 180 fps | 1/167 s | 1/333 s | 1/1000 s | 1/1000 s |
| 240 fps | 1/250 s | 1/500 s | 1/1000 s | 1/1000 s |
Why 180° is the default
A 180° shutter gives motion blur that matches how the eye reads movement at 24 fps. Narrow the angle (90°, 45°) and you get crisper frames that survive slow motion and look like Saving Private Ryan; open it to 360° and motion smears, which suits dream sequences and low light.
Frame rate and shutter angle together decide whether lights flicker. At 50 Hz mains, shoot 25 or 50 fps; at 60 Hz, shoot 30 or 60 fps. On mixed or unknown lighting, a narrow angle lets you keep 24 fps without banding.