Calculate the physical area of a circular aperture or camera opening.
Aperture Parameters
Calculation Results
Enter parameters to calculate
About this calculator
Quick Reference
DDiameter
fFocal Length
Nf-number (f-stop)
D (photo)f / N
Overview
In optics and photography, aperture area determines how much light enters the system. It is simply the area of the circular opening, but it can be derived from the diameter or the lens focal length and f-stop.
💡
Pro Tips
Each 'stop' in photography (e.g., from f/2 to f/2.8) represents a doubling or halving of the aperture area.
A larger area allows for an shallower depth of field and better low-light performance.
The aperture area is proportional to the square of the diameter; doubling the diameter quadruples the area.
!
Fun Facts
"The 'f' in f/stop stands for focal length. An aperture of f/2 means the diameter is exactly half the focal length."
"The human pupil can vary in area by a factor of about 15, from a diameter of 2mm in bright light to 8mm in total darkness."
"The largest telescope aperture in the world (the ELT) will have an area of nearly 1,000 square meters!"
