Crop Factor Calculator
Convert focal length and aperture to full-frame equivalents using your sensor's crop factor, with presets for full-frame, APS-C, and Micro Four Thirds.
A 35 mm lens on a 1.5× APS-C body frames like roughly a 53 mm lens on full frame. The equivalent aperture describes the matching depth of field and total light, not the exposure brightness, which stays at the marked f-number.
How it works
A crop factor describes how much smaller your sensor is than full frame. A smaller sensor sees a narrower slice of the lens's image circle, so the view looks more zoomed in than the focal length printed on the barrel would suggest.
Multiply your focal length by the crop factor and you get the full-frame equivalent — the focal length a full-frame camera would need to frame the same shot. A 35 mm lens on a 1.5x APS-C body frames like a 53 mm lens on full frame.
The tool also multiplies the aperture by the crop factor to give an equivalent f-number. That equivalent describes the matching depth of field and total light gathered, which is why smaller sensors struggle to blur backgrounds the way full frame does.
Frequently asked questions
Does crop factor change my exposure?
No. Your marked f-number still controls brightness exactly as printed, so f/1.8 is f/1.8 for exposure. The equivalent aperture only describes depth of field and total light, not how bright the frame is.
Which crop factor is mine?
Full frame is 1.0, most APS-C cameras are 1.5, Canon APS-C is 1.6, and Micro Four Thirds is 2.0. Pick the preset that matches your body, or type a custom value for anything unusual.
Why does full frame blur backgrounds more?
For the same framing, a bigger sensor uses a longer actual focal length, which produces shallower depth of field. That's the equivalent-aperture effect, and it's why portrait shooters love full frame.