Exposure Value (EV) Calculator
Use this exposure calculator to find the exposure value (EV) of any aperture, shutter speed and ISO, and see what kind of light it suits. EV is a single number that sums up the three sides of the exposure triangle, making it easy to compare settings and apply rules of thumb like Sunny 16.
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Calculate exposure value
Enter values above and press Calculate to see your result.
Formula used
Exposure value combines aperture (N) and shutter time (t in seconds):
EV = log₂(N² ÷ t)
To compare across sensitivities, adjust to an ISO 100 reference:
EV₁₀₀ = EV − log₂(ISO ÷ 100)
Higher EV means brighter light. The Sunny 16 rule says bright sun is about EV 15 at ISO 100 (f/16 with shutter ≈ 1/ISO). Each whole EV step is one stop — a halving or doubling of light.
Worked examples
Sunny 16. f/16, 1/100 s, ISO 100 ≈ EV 14.6 — bright daylight.
Indoors. f/2.8, 1/60 s, ISO 100 ≈ EV 7.4 — dim interior light.
Night street. f/2, 1/30 s, ISO 1600 ≈ EV 3 at ISO 100 reference.
How to use this calculator
- Enter the aperture (f-number) you're using.
- Enter the shutter speed and choose 1/x or whole seconds.
- Enter the ISO.
- Press Calculate to see the EV, the ISO 100 reference EV, and a typical scene.
EV (at ISO 100) and typical light
| EV₁₀₀ | Lighting | Sunny 16 setting (1/100, ISO 100) |
|---|---|---|
| 16 | Snow / bright sand | f/22 |
| 15 | Bright sunlight | f/16 |
| 14 | Hazy sun / soft shadows | f/11 |
| 12 | Overcast / bright shade | f/5.6 |
| 9–10 | Sunset, open shade | f/2.8 |
| 5–7 | Bright indoors | — |
Each stop down in aperture (or step in shutter/ISO) changes EV by one.
Who should use this calculator
Photographers learning the exposure triangle, film shooters without a meter relying on Sunny 16, and anyone wanting to compare two settings on the same scale. It's a great teaching tool for understanding how aperture, shutter and ISO trade off.
Understanding the exposure triangle
Aperture controls depth of field, shutter speed controls motion blur, and ISO controls sensitivity (and noise). EV ties them together: any combination giving the same EV (at the same ISO) produces the same brightness. That's why you can open the aperture one stop and speed up the shutter one stop for an identical exposure with different creative effect.
Using Sunny 16 in the field
On a bright sunny day, set the aperture to f/16 and the shutter to 1/ISO (e.g. 1/100 s at ISO 100) for a correct exposure — roughly EV 15. Open up one stop for hazy sun, two for overcast, and three for open shade. The EV here helps you sanity-check a meterless exposure.
Limitations of this calculator
EV describes a brightness level, not a guaranteed correct exposure for your subject — backlighting, very dark or bright subjects, and creative intent all matter. Treat EV and Sunny 16 as reliable starting points, and use your histogram to confirm.
Frequently asked questions
What is exposure value (EV)?
EV is a single number summarising a combination of aperture and shutter speed (referenced to an ISO). Higher EV means brighter conditions; each whole step is one stop of light.
What is the Sunny 16 rule?
In bright sun, set aperture to f/16 and shutter to 1 over your ISO (e.g. 1/100 s at ISO 100) for a correct exposure — about EV 15.
How does ISO affect EV?
Raising ISO lets you shoot in lower EV (darker) conditions. The EV₁₀₀ value normalises everything to ISO 100 so settings are comparable.
Do different settings with the same EV look identical?
In brightness, yes — but depth of field and motion blur differ. f/2.8 at 1/500 and f/8 at 1/60 can share an EV yet look very different creatively.
Is a higher EV brighter or darker?
Higher EV corresponds to brighter light and therefore smaller apertures or faster shutters to expose correctly.