Aperture, Shutter Speed, ISO Calculatorv1.0.0

Calculate the correct exposure for any lighting condition by working with the three variables of the exposure triangle: aperture, shutter speed, and ISO. Compute the exposure value (EV) from all three settings, or solve for a single missing variable when the other two and a target EV are provided.

• Choose a Calculation Mode at the top of the form. Select Calculate EV to find the exposure value from all three settings, or pick Solve for Aperture, Solve for Shutter Speed, or Solve for ISO to find the missing variable.
• Set the Aperture from the dropdown. Standard f-stops from f/1 to f/64 are listed, and the Custom option accepts any f-number, including third-stop values such as 6.3 or 3.2.
• Set the Shutter Speed from the dropdown. Values range from 1/4000 second to 60 seconds, and the Custom option accepts fractions such as 1/320 or decimals such as 0.5.
• Set the ISO Sensitivity from the dropdown. Standard values from ISO 25 to ISO 102400 are available, or enter a custom number.
• Enter a Target EV when solving for a variable. Refer to the EV Reference Table for guidance, where bright sunlight is around EV 15, overcast skies around EV 10, and dim indoor lighting around EV 5.
• Press Calculate to update results, or rely on the automatic 500-millisecond debounce that recalculates as inputs change.
• Open the advanced settings to enable the step-by-step derivation, which applies the formula EV = log2(100 * aperture^2 / (ISO * shutter speed)).
• Enable equivalent exposures to view alternative aperture, shutter speed, and ISO combinations that produce the same exposure value.
• Press Reset to restore all defaults and clear stored values.

Apply the exposure triangle calculator across a wide range of photography scenarios, from planning a shoot in advance to recovering from unexpected lighting in the field. Photographers at every skill level benefit from a clear mathematical view of how aperture, shutter speed, and ISO interact to determine exposure.

• Landscape photography: Calculate the required shutter speed for a waterfall scene at f/16 and ISO 100. Decide whether a neutral density filter is needed by checking whether the solved shutter exceeds your handheld limit.
• Astrophotography: Set a target EV of -6 for the Milky Way and solve for the ISO that pairs with a wide aperture such as f/1.4 and a 20-second exposure dictated by the 500 rule.
• Sports and action: Lock in a fast shutter speed such as 1/1000 second and solve for the aperture and ISO combination that achieves correct exposure under stadium lighting at roughly EV 8.
• Portrait photography: Choose a wide aperture such as f/2.8 for shallow depth of field, then solve for the shutter speed at your preferred ISO to keep handheld results sharp.
• Education: Demonstrate how the exposure triangle works by reviewing equivalent exposures. Changing aperture by one stop and compensating with shutter speed produces identical exposure values, which makes the relationship visible and intuitive.
• Film photography: Pre-calculate exposure settings for a film stock with a fixed ISO. Enter the film speed and the target EV for the shooting environment to find a workable aperture and shutter combination before loading the roll.
• Video production: Solve for aperture or ISO when the shutter is constrained by the 180-degree rule. For 24 fps footage, the shutter is locked at 1/48 second, so the other two variables must adapt.
• Event photography: Adapt quickly to changing lighting by entering a new target EV and solving for the variable you choose to adjust, leaving the others fixed for consistency.