Lens Magnification and Depth of Field Calculator

Which of my lenses is best suited for macro photography? How much would a lens extension tube improve the situation? What depth of field can be expected?

Here is an easy to use calculator for these questions. Just enter the focal length of your lens, distance to your subject and selected f-stop, and see what happens. The calculator works both online and offline.

focal length mm
focus distance m
extension tube mm
circle of confusion mm, or select
magnification x
effective focus distance m with extension tube
depth of field m – m
angle of view ° diagonal
hyperfocal distance m
minimum subject size mm at infinity focus
image distance mm
subject distance mm

How does it work? Here’s the theory behind it.