Aperture (f-number) Enter the f-number (e.g., 2.8, 5.6, 16)

Shutter Speed (seconds) Enter shutter speed in seconds (e.g., 0.001 for 1/1000s, 0.0333 for 1/30s)

ISO Enter ISO sensitivity (e.g., 100, 400, 1600)

Quick Examples:

Sunny Daylight Indoor Low-Light

Calculate Clear

This calculator is for informational and educational purposes only. Results are based on standard photographic formulas and may not account for all real-world shooting conditions. Verify exposure settings with your camera's light meter for critical work.

Use this free online Exposure Value Calculator to calculate your exposure value (EV). Simply enter your aperture, shutter speed, and ISO to instantly get results in EV (stops). This value helps you understand the overall brightness level of your exposure settings and compare different camera configurations.

How Exposure Value Is Calculated

Exposure Value (EV) is a number that represents the combination of aperture and shutter speed as a single value. A higher EV means less light reaches the sensor, which happens with smaller apertures or faster shutter speeds. A lower EV means more light reaches the sensor. The calculator adjusts for ISO so you can compare exposures at different sensitivity settings.

The formula squares the aperture because each f-stop represents a doubling or halving of light. The result is divided by shutter speed to account for exposure time. The ISO adjustment normalizes everything to ISO 100, which is the standard reference for EV values.

What Your Exposure Value Result Means

Your EV number tells you about the lighting conditions and helps you find equivalent exposure settings. A bright sunny day typically produces an EV around 15, while a dimly lit indoor scene might be around EV 5 to 7. Each whole EV number represents a doubling or halving of light, called one "stop."

Use the EV value to compare different exposure combinations. Any settings with the same EV will produce the same brightness in your photo. For example, f/8 at 1/125s and f/4 at 1/500s both give EV 13 at ISO 100.

Accuracy, Limitations & Common Mistakes of the Exposure Value Calculator

How Accurate Is the Exposure Value Calculator?

The calculator uses standard photographic formulas that are widely accepted in the industry. Results are mathematically precise based on the inputs you provide. However, real-world exposure depends on many factors this calculator cannot measure, such as scene reflectance, lens transmission loss, and sensor characteristics.

Limitations of the Exposure Value Calculator

This calculator does not account for lens light transmission differences (T-stops versus f-stops), which can vary between lenses. It also does not consider scene reflectance, subject tonality, or metering modes. Very long exposures may experience reciprocity failure with film, which this calculator does not address. The results assume standard daylight color temperature.

Common Mistakes to Avoid

• Entering shutter speed in the wrong format. Use decimal seconds, not fractions. For example, enter 0.008 for 1/125 second, not 1/125.
• Forgetting that lower EV numbers mean brighter scenes. EV 15 is bright sunlight, while EV 5 is much darker.
• Ignoring the ISO adjustment. EV at your actual ISO differs from EV at ISO 100. The calculator shows both values to help you understand the difference.

Frequently Asked Questions

Who is this Exposure Value Calculator for?

This calculator is for photographers of all skill levels who want to understand exposure relationships. It is useful for film photographers without built-in meters, digital photographers learning manual exposure, and anyone who wants to compare different camera settings for the same lighting conditions.

How often should I use this calculator?

Use this calculator when planning shoots, learning about exposure, or when your camera meter is not available. Many photographers use it to pre-visualize settings before arriving at a location, or to understand equivalent exposures without changing settings on their camera.

Does this calculator work for all camera types?

Yes, the exposure value formula applies to all cameras, including DSLRs, mirrorless cameras, film cameras, and medium format systems. The physics of exposure remain the same regardless of camera type or sensor size.

Can I use this calculator for video exposure?

Yes, the exposure value formula works for video as well. However, video often requires specific shutter speeds based on frame rate, typically twice the frame rate for natural motion blur. You may need to adjust aperture or ISO to achieve proper exposure with fixed shutter speeds.

Is the Exposure Value Calculator free to use?

Yes, this calculator is completely free to use with no sign-up required. It works on any device with a web browser.