Focal Length Aperture Diameter and FStop Calculator

This calculator helps you calculate aperture diameter and f-stop values based on focal length and aperture diameter, essential for photography and optics calculations.

Input Parameters

Calculation Results

Calculation Results

F-Stop (f/#): -

Calculation Formula

F-Stop (f/#) = Focal Length / Aperture Diameter

Where:
F-Stop: The f-number of the lens
Focal Length: The distance from the optical center of the lens to the image sensor
Aperture Diameter: The diameter of the aperture opening in the lens

Focal Length Aperture Diameter and FStop Calculator Usage Guide

Learn how to use the calculator and understand the relationships between focal length, aperture diameter, and f-stop in photography.

How to Use This Calculator

  1. Enter the focal length of your lens in millimeters (mm).
  2. Enter the aperture diameter of your lens in millimeters (mm).
  3. Select whether you want to calculate the F-Stop or the Aperture Diameter from the F-Stop.
  4. Click the "Calculate" button to get the result.
  5. Use the "Reset" button to clear all inputs and start over.

Understanding the Formulas

The calculator uses the fundamental relationship between focal length, aperture diameter, and f-stop:

F-Stop (f/#) = Focal Length / Aperture Diameter

This means if you know two of these values, you can calculate the third.

Practical Applications

  • Determining the f-stop value when you know the focal length and aperture diameter.
  • Calculating the aperture diameter needed for a specific f-stop when you know the focal length.
  • Understanding how changing the aperture diameter affects the depth of field in photography.
  • Comparing the light-gathering ability of different lenses.

Example

If you have a 50mm lens with an aperture diameter of 25mm:

F-Stop = 50mm / 25mm = 2.0

This would be written as f/2.0.