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Exposure Triangle Calculator
Balance aperture, shutter speed, and ISO to achieve a target exposure and compare common photographic trade-offs.
This works right here on your device — nothing gets sent out.
Exposure Triangle Calculator
Pick which setting to solve for — the other two are held fixed and the exposure stays balanced.
Exposure value (EV, at ISO 100):
Change either fixed field and the solved field updates automatically to keep this EV constant.
Equivalent exposures
Other aperture/shutter combinations at the same ISO that produce the same exposure.
| Aperture | Shutter speed | Trade-off |
|---|
How Exposure Triangle Calculator works
- Choose which setting you want solved for automatically: aperture, shutter speed, or ISO.
- Set the other two fields, or load a scene preset (Sunny 16, Overcast, Indoors, Night sky) to start from a realistic exposure.
- The solved field updates instantly to the exact value that keeps the exposure value (EV) unchanged from whatever it was before you changed anything.
- Check the "Equivalent exposures" table for other aperture/shutter combinations at the same ISO that produce the same brightness, with the depth-of-field and motion-blur trade-off for each.
- Use "Copy settings" to grab a plain-text summary of the current aperture, shutter speed, ISO, and EV.
The formula
Exposure value at ISO 100 is calculated from the standard APEX formula:
EV100 = log2(N² / t) - log2(S / 100)
where N is the f-number, t is shutter time in seconds, and S is ISO speed. Solving this equation for whichever setting you've selected keeps EV100 — and therefore overall brightness — constant while the other two change.
FAQ
What is the exposure triangle?
The exposure triangle is aperture, shutter speed, and ISO — the three camera settings that together determine how bright a photo is. Changing one shifts the exposure, so photographers adjust another to compensate: a wider aperture lets in more light, so a faster shutter speed or lower ISO can bring the exposure back to the same brightness.
How do I calculate an equivalent exposure?
An equivalent exposure keeps the overall brightness the same while trading one setting for another. This calculator does that automatically: pick which of the three settings to solve for, change either of the other two, and the solved field updates to the exact value that preserves the current exposure value (EV).
What is a "stop" in photography?
A stop is a doubling or halving of light. Each step on the standard aperture, shutter speed, or ISO scale used in this calculator (f/8 to f/11, 1/125s to 1/60s, ISO 100 to ISO 200) is one full stop — moving one stop on any setting requires a one-stop change on another to keep the same exposure.
What is the Sunny 16 rule?
A well-known daylight exposure guideline: on a bright sunny day, set aperture to f/16 and shutter speed to roughly 1/ISO (e.g. 1/100s at ISO 100) for a correctly exposed shot. It's a starting point, not an exact meter reading — the "Sunny 16" preset above loads this combination so you can see its exposure value and equivalent settings.
Does changing ISO affect image quality, not just exposure?
Yes. Unlike aperture (which changes depth of field) and shutter speed (which changes motion blur), ISO doesn't change what light reaches the sensor — it amplifies the signal. Higher ISO brightens the image but introduces more visible noise, so photographers generally prefer the lowest ISO that still allows a usable aperture and shutter speed.
How we compare
| Feature | Online Tool Store | MiniWebTool Exposure Triangle Calculator | DailyPhotoTips Exposure Calculator |
|---|---|---|---|
| Solve for any of aperture, shutter speed, or ISO | Included | Change one, get the other two | Solve for one from two inputs |
| Live equivalent-exposure table with depth-of-field/motion-blur trade-offs | Included | Included | Included |
| Built-in scene presets (Sunny 16, Overcast, Indoors, Night sky) | Included | Portrait/action-style presets | Not included |
| Exposure value (EV) shown directly, normalized to ISO 100 | Included | Stop-shift shown, no raw EV | Included |
| Copy a plain-text result summary | Included | Not included | Not included |
| Runs fully in your browser, nothing uploaded | Included | Included | Included |
Choose Exposure Triangle Calculator when you want a single always-balanced triangle — pick what to solve for, adjust the rest freely, and see equivalent exposures update live.