Exposure Calculator — Photography EV Calculator
Find the Exposure Value (EV) for any aperture, shutter speed and ISO combination. See whether your settings suit bright sunlight, overcast sky, indoor shooting or night photography — and understand how many stops you are from a reference scene.
Aperture
Shutter speed
ISO sensitivity
EV at ISO 100 — the scene luminance your settings capture
- 1
Exposure time
1 ÷ 125 = 0.008Shutter speed converted to seconds. - 2
EV (camera settings)
log₂(5.6² ÷ 0.008) = 11.94 - 3
ISO correction
log₂(100 ÷ 400) = -2Adjusts camera EV to the ISO 100 reference scale. - 4
EV at ISO 100
11.94 + (-2) = 9.9
How does this calculator work?
EV = log₂(N²/t) where N is the f-number and t is the shutter speed in seconds; add log₂(ISO/100) to account for sensor sensitivity. Sunny daylight is EV ≈ 14 at ISO 100; overcast is EV ≈ 12; dim indoors EV ≈ 6. The calculator maps your aperture/shutter/ISO combination to a scene-brightness scale.
Formula
How this is calculated
Exposure Value (EV) is a standardised way to express the total light a camera captures, combining aperture, shutter speed and ISO into a single number. The base formula EV = log₂(N² / t) captures only the lens and shutter: N is the f-number (aperture) and t is the exposure time in seconds. A higher EV means less light reaches the sensor (small aperture, fast shutter); a lower EV means more light (wide aperture, long exposure).
ISO sensitivity adds extra stops: EV_ISO = EV + log₂(ISO / 100). Doubling the ISO is equivalent to opening one extra stop. The "EV at ISO 100" shown here is the scene luminance value (also called Light Value or LV by some manufacturers) referenced to the ISO 100 standard — the number used when a photographer says "sunny day is EV 14".
The Sunny 16 rule says a sunny scene needs approximately EV 14 at ISO 100: aperture f/16, shutter 1/100 s (or equivalent). At EV 12, a scene is overcast; at EV 6–8, it is a dimly lit interior; below EV 0, it is a moonlit or star-lit night. The coloured range meter shows where your settings fall on this scale so you can judge whether they are appropriate for the scene.
Frequently asked questions
The Sunny 16 rule is a classic exposure guideline: on a bright sunny day, set aperture f/16 and use a shutter speed equal to 1/ISO (so 1/100 s at ISO 100, 1/400 s at ISO 400). This gives EV ≈ 14 at ISO 100, which is correct for direct sunlight on a clear day.
Settings with the same EV capture the same total amount of light — they produce an identically exposed image on average. However, they differ in depth of field (wider aperture → shallower DOF), motion blur (slower shutter → more blur), and noise (higher ISO → more noise). Equivalent exposures let you choose the creative trade-off.
ISO amplifies the sensor signal, effectively making it more sensitive to light. Doubling ISO is one extra stop of sensitivity — you need one stop less light (half the exposure time, or one stop smaller aperture) to get the same brightness. So raising ISO increases the EV captured from the same scene, at the cost of added digital noise.
Also known as
TG we-Calculate Editorial Team. (2026). Exposure Calculator — Photography EV Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/exposure-calculator
TG we-Calculate Editorial Team. "Exposure Calculator — Photography EV Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/exposure-calculator.
TG we-Calculate Editorial Team, "Exposure Calculator — Photography EV Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/exposure-calculator
@misc{wecalculate_exposure_calculator, title = {Exposure Calculator — Photography EV Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/exposure-calculator}}, year = {2026}, note = {TG we-Calculate} }
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