📷 Photography
ND Filter Calculator
An ND filter cuts light by a fixed number of stops, so the correct exposure is the unfiltered shutter speed multiplied by two to the power of the stop count. A 10-stop filter therefore turns 1/500 s into about 2 seconds — which is why long-exposure photography needs a tripod and a remote release rather than steady hands.
How it works
Shutter speed without filter
Filter strength
Shutter speed with filter
Exposure increase
Stops reduced
Shutter speed reading
Original shutter speed reading
Frequently asked questions
How do I use the ND Filter Calculator?
Fill in the fields above — the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.