# Shutter Speed Calculator

URL: https://speedycalculator.com/calculators/other/shutter-speed/
Last updated: 2026-10-30

> The shutter speed calculator recommends the exposure time for a lighting situation – from the Milky Way to bright snow – at your chosen aperture and ISO, rounds it to the nearest shutter speed your camera offers and checks whether you can hand-hold it.

## Inputs

- Lighting condition
- Exposure value (EV at ISO 100)
- Aperture — Marked f-numbers are rounded; the calculator uses the exact values (f/22 is really f/22.63).
- f-number (N)
- ISO sensitivity
- ISO value
- Focal length (for the hand-holding check, optional) (mm, cm, in)
- Crop factor — 1 for full frame, 1.5 or 1.6 for APS-C, 2 for Micro Four Thirds.

## Results

- Shutter speed (exact)
- Nearest camera setting
- Exposure time in seconds
- Lighting
- Focal ratio used
- Hand-holding check
- Stops slower than the hand-holding limit

## Formula

```
t = 100 · N² ÷ (ISO · 2^EV) · hand-holding limit ≈ 1 ÷ (focal length × crop factor) seconds
```

## Explanation

Shutter speed is how long the sensor is exposed to light. Together with the aperture and ISO it fixes the exposure, so once you know how bright a scene is – its exposure value – you can calculate the shutter speed that gives a correct exposure for any aperture and ISO. Fast speeds such as 1/1000 s freeze sport and wildlife; slow speeds of several seconds blur water, draw light trails and gather enough light for night skies.

Each lighting preset in this calculator stands for a typical exposure value at ISO 100: a sunlit beach is EV 16, an overcast day EV 12–13, a lit street at night EV 7 and the Milky Way EV −7. Pick the scene (or type your own meter reading), choose the aperture and ISO, and the calculator gives the exact time and the closest standard setting in third stops. Long exposures beyond 30 seconds are shown in minutes for bulb mode.

Add your focal length and crop factor to check against the reciprocal rule – a quick guide to the slowest speed you can hand-hold without visible shake. If the result is slower, use a tripod, image stabilisation, a wider aperture or a higher ISO.

### How to use the Shutter Speed Calculator

- **Lighting condition**
- **Exposure value (EV at ISO 100)**
- **Aperture** — Marked f-numbers are rounded; the calculator uses the exact values (f/22 is really f/22.63).
- **f-number (N)**
- **ISO sensitivity**
- **ISO value**
- **Focal length (for the hand-holding check, optional)**
- **Crop factor** — 1 for full frame, 1.5 or 1.6 for APS-C, 2 for Micro Four Thirds.

Everything is calculated in your browser, so results appear instantly and nothing you type is sent to a server.

### How it works

The exposure equation EV = log₂(100·N²/(ISO·t)) is solved for t. The result is matched to the nearest third-stop shutter speed and compared with 1/(focal length × crop factor) for hand-holding.

### Worked example

Open shade (EV 12) at f/4 and ISO 200: t = 100 × 4² ÷ (200 × 2¹²) = 1600 ÷ 819,200 = 1/512 s, so set 1/500 s.

At night under the Milky Way (EV −7) with f/2.8 (exact 2.828) and ISO 6400: t = 100 × 8 ÷ (6400 × 2⁻⁷) = 800 ÷ 50 = 16 s. With a 14 mm full-frame lens the hand-holding limit is 1/14 s, so a tripod is essential.

### Shutter speeds for common subjects

SubjectTypical shutter speedBirds in flight1/2000 s or fasterSport, running children1/1000 sWalking people1/250 sHand-held 50 mm1/60 sSilky waterfall1/2–2 sLight trails10–30 sMilky Way, wide lens10–25 s

## Worked example

Inputs — Lighting condition: EV 15 – Bright sun, clear sky; Aperture: f/8; ISO sensitivity: ISO 100; Focal length (for the hand-holding check, optional): 50 mm; Crop factor: 1.

Results — **Shutter speed (exact) = 1/512 s**; Nearest camera setting = 1/500 s; Exposure time in seconds = 0.001953; Lighting = EV 15 – Bright sun, clear sky (Sunny 16); Focal ratio used = 8; Hand-holding check = Slowest safe hand-held speed ≈ 1/50 s – hand-held is fine.

## Key terms

- **Shutter speed**: The time the sensor is exposed to light, written in seconds or fractions of a second.
- **Reciprocal rule**: Hand-hold no slower than 1/(equivalent focal length) seconds.
- **Bulb mode**: Keeps the shutter open as long as the button or remote is held.

## FAQ

**What shutter speed should I use in bright sun?**
At f/16 and ISO 100, about 1/125 s (EV 15) – the Sunny 16 rule. At f/8 it becomes 1/500 s.

**What shutter speed for the Milky Way?**
At EV −7, f/2.8 and ISO 6400 the calculation gives 16 s. Keep it under about 20 s with a wide lens to avoid star trails.

**What is the slowest shutter speed I can hand-hold?**
Roughly 1/(focal length × crop factor): 1/50 s with a 50 mm lens on full frame, 1/80 s on APS-C. Stabilisation adds 3–5 stops.

**What shutter speed freezes motion?**
1/250 s for walking people, 1/1000 s for running and sport, 1/2000 s or faster for birds in flight.

**Why does my result say 1/512 s?**
The exact calculation rarely lands on a marked value; use the nearest camera setting shown (1/500 s).

**How do I take exposures longer than 30 seconds?**
Use bulb mode with a remote release and time the exposure; the calculator shows minutes and seconds for long times.


## Sources

- [Wikipedia – Shutter speed](https://en.wikipedia.org/wiki/Shutter_speed)
- [Wikipedia – Exposure value](https://en.wikipedia.org/wiki/Exposure_value)
- [Wikipedia – Sunny 16 rule](https://en.wikipedia.org/wiki/Sunny_16_rule)