🔆 Sunny 16 Exposure Calculator
Enter your ISO and aperture to get the right shutter speed for every light condition, using the Sunny 16 rule.
| Light condition | Rule aperture | Shutter at f/16 |
|---|---|---|
| Snow / bright sand | f/22 | 1/50 s |
| Bright sun (Sunny 16) | f/16 | 1/100 s |
| Hazy / soft shadows | f/11 | 1/200 s |
| Cloudy bright | f/8 | 1/400 s |
| Overcast / open shade | f/5.6 | 1/800 s |
| Heavy overcast / sunset | f/4 | 1/1600 s |
The Sunny 16 rule: in bright sun at f/16, the shutter is about 1⁄ISO seconds (ISO 100 → 1/100 s). The table adjusts that for softer light and your chosen aperture — a handy way to nail exposure without a meter. It measures incident light, so it\'s a starting point, not a substitute for metering. 🔒 In your browser.
How the sunny 16 exposure calculator works
The Sunny 16 rule says that in bright sunlight at f/16, the correct shutter speed is about 1 ÷ ISO seconds. From that anchor, each softer light condition needs one more stop of light (a wider aperture or slower shutter). The tool builds the table for your ISO and chosen aperture, so you can expose by eye.
It's a starting point based on incident sunlight, not a replacement for a meter — but it's remarkably reliable outdoors and a great way to learn how aperture, shutter and ISO relate. It also rescues you when a meter fails or you're shooting film without one.
Frequently asked questions
What is the Sunny 16 rule?
A guideline for exposure without a meter: in bright sun, set the aperture to f/16 and the shutter speed to 1 ÷ ISO seconds (ISO 100 → 1/100 s). Softer light needs wider apertures or slower shutters.
How does Sunny 16 work for cloudy weather?
Each step of softer light opens up by a stop from f/16: f/11 for hazy sun, f/8 for cloudy-bright, f/5.6 for overcast, f/4 for heavy overcast or open shade. The tool shows the matching shutter for your settings.
What shutter speed for ISO 400 in sun?
By Sunny 16, about 1/400 s at f/16 in bright sun. At f/8 (two stops brighter) you'd use 1/1600 s to keep the same exposure. The tool calculates it for any ISO and aperture.
Is the Sunny 16 rule accurate?
Surprisingly so for outdoor daylight — it's based on the fairly constant intensity of direct sunlight. It's a reliable starting point, though you should adjust for backlight, very light or dark subjects, and check results.
Why learn Sunny 16 with modern cameras?
It teaches how aperture, shutter and ISO trade off, gives you a sanity check on your meter, and lets you shoot confidently in tricky metering situations or with fully manual/film cameras.