Free Film & Video Tool · Calculator
Shutter Angle Calculator
Convert shutter angle to shutter speed (and back) at any frame rate, including 23.976 and 29.97 fps — with exact exposure times, nearest camera shutter speeds and flicker-safe options.
Deterministic maths that runs entirely in your browser — no AI model, no uploads, no account. Formulas and assumptions are explained below the calculator.
Inputs
Results update as you type.
Fractional rates such as 23.976 and 29.97 are supported.
Between 0° and 360°.
Results
Shutter speed
1/48 s
at 24 fps and 180°
Exposure time
0.02083 s (20.83 ms)
Share of each frame exposed
50%
Same exposure as 180°
Nearest common camera setting
1/48 s
= 180° at 24 fps
Motion blur
Matches the common 180° convention — the familiar ‘film-like’ motion blur.
Flicker-safe shutter angles at 24 fps (50 Hz mains)
86.4° · 172.8° · 259.2° · 345.6°
For lights that pulse at twice the mains frequency. Many LED fixtures behave differently — always test with your actual lights.
How it works
Shutter angle describes exposure time as a fraction of each frame. The name comes from film cameras, whose rotating shutter was a disc with an open segment: a 180° opening exposes each frame for half of its frame interval. Digital cinema cameras often show shutter angle, while stills and hybrid cameras usually show shutter speed — this calculator converts between the two.
The formulas
- Exposure time (seconds) = shutter angle ÷ (360 × frame rate)
- Shutter speed (1/x): x = (360 × frame rate) ÷ shutter angle
- Shutter angle (degrees) = 360 × frame rate × exposure time
Worked examples
| Frame rate | Shutter angle | Shutter speed | Notes |
|---|---|---|---|
| 24 fps | 180° | 1/48 s | 1/50 s on most hybrid cameras (172.8°) |
| 25 fps | 180° | 1/50 s | Also flicker-safe on 50 Hz mains |
| 24 fps | 90° | 1/96 s | One stop less light than 180° |
| 23.976 fps | 180° | 1/47.952 s | Cameras typically round to 1/48 or 1/50 |
| 29.97 fps | 180° | 1/59.94 s | Usually set as 1/60 s |
| 50 fps | 360° | 1/50 s | The longest possible exposure at 50 fps |
The 180-degree convention (not a rule)
A 180° shutter — a shutter speed of roughly double the frame rate — produces the amount of motion blur most audiences associate with “cinematic” movement. It's a sensible default, not a requirement. Filmmakers deliberately choose narrower angles (45°–90°) for jittery, high-energy action and battle scenes, and wider angles (up to 360°) for dreamier smearing or to gain light in dim conditions. If you change the angle for exposure rather than for look, remember that every halving of the angle costs one stop of light.
Flicker-safe angles
Many artificial lights pulse at twice the mains frequency — 100 times a second on 50 Hz power and 120 on 60 Hz. An exposure that lasts a whole number of those pulses records the same amount of light on every frame, so the calculator lists the angles that do that at your frame rate (for example 172.8° at 24 fps on 50 Hz, or 144° at 24 fps on 60 Hz). LED fixtures, monitors and some practicals use their own drivers and can flicker at other frequencies, so always test with your actual lights.
Assumptions and limitations
- The conversion is exact for the frame rate you enter; fractional NTSC rates are used as typed (23.976, not 24000/1001).
- Cameras only offer certain shutter speeds or angles, so the “nearest common camera setting” is a guide. Check what your camera actually allows.
- Rolling-shutter skew, electronic shutter behaviour and motion-blur rendering in post aren't modelled.
- The shutter doesn't change with variable-frame-rate recording or speed ramps — recalculate for each capture frame rate. For slow motion, see our slow-motion guide.
FAQ
- What shutter speed is 180 degrees at 24fps?
- 1/48 second. The formula is shutter angle ÷ (360 × frame rate), so 180 ÷ (360 × 24) = 1/48 s. Many stills-style cameras can't set 1/48, so 1/50 (172.8°) is the usual nearest setting.
- Do I have to use a 180-degree shutter?
- No. 180° is a convention that gives motion blur most audiences read as natural, not a rule. Narrower angles give crisper, more staccato motion; wider angles give smoother, more smeared motion and an extra stop of light at 360°.
- Why can't I set a shutter speed slower than 1/frame rate?
- Each frame can only be exposed for as long as the frame lasts. At 24 fps that's 1/24 s, which is a 360° shutter — the maximum this calculator allows.
- How do I keep a 180° shutter outdoors?
- Because the shutter speed is fixed by the frame rate, control exposure with ND filters, aperture or ISO rather than a faster shutter.
- Is it free to use?
- Yes. There's no signup or account, and the calculations run entirely in your browser — nothing you type is sent to a server or an AI model.
- Can I share or save my results?
- Yes. Your inputs are saved in the page address as you type, so “Copy link” gives you a URL that reopens the calculator with the same settings. “Copy results” copies a plain-text summary.
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