Crop Factor Calculator
Find the 35mm equivalent focal length and effective aperture for any camera sensor.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Crop Factor Calculator
- Enter your lens's focal length in millimeters. This is the number printed on the lens barrel (e.g. 35mm, 50mm, 85mm).
- Enter the aperture (optional). When you fill in the f-number, the calculator also shows the equivalent full-frame aperture for matching depth of field.
- Select your sensor size. APS-C Nikon/Sony use 1.5x, APS-C Canon use 1.6x, Micro Four Thirds use 2.0x. If you know your specific crop factor, use Custom.
- Read the equivalent focal length. This is what your lens behaves like on a full-frame camera in terms of field of view.
About Crop Factor
Crop factor is the ratio of a full-frame sensor's diagonal (43.27mm) to the diagonal of a smaller sensor. A 1.5x crop sensor captures a narrower field of view than full frame at the same focal length, making every lens appear to have a longer equivalent focal length. A 35mm lens on a 1.5x APS-C body behaves like a 52.5mm lens on full frame.
Crop factor also affects depth of field. To achieve the same field of view and the same depth of field on a 1.5x crop sensor, you need to multiply both the focal length and the aperture by 1/1.5. A full-frame 50mm f/1.8 combo matches a crop-sensor 33mm f/1.2 combo in both field of view and depth of field. This is why APS-C shooters often find that full-frame lenses offer more background separation at equivalent fields of view.
Frequently Asked Questions
What is the crop factor of APS-C cameras?
Most APS-C cameras from Nikon, Sony, and Fujifilm use a 1.5x crop factor. Canon APS-C cameras use a slightly larger 1.6x crop factor. This means a 50mm lens on a Canon APS-C body has an 80mm full-frame equivalent field of view.
Does crop factor affect lens sharpness or image quality?
Crop factor does not directly affect sharpness. It changes the effective field of view and, when comparing equivalent scenes, affects depth of field and low-light performance because of sensor size differences. A smaller sensor typically collects less total light, which can result in more visible noise at high ISO settings compared to a full-frame sensor at the same aperture.
What is the equivalent of a 50mm lens on APS-C?
A 50mm lens on a 1.5x APS-C camera (Nikon, Sony, Fujifilm) gives a 75mm full-frame equivalent field of view. On a Canon APS-C (1.6x crop), it gives 80mm equivalent. To get the classic 50mm "normal" field of view on APS-C, use a 33-35mm lens.
What does the equivalent aperture mean?
The equivalent aperture shows the f-number a full-frame lens would need to produce the same depth of field. A 35mm f/1.8 on a 1.5x APS-C sensor has an equivalent aperture of f/2.7 in depth-of-field terms — you would need a 52.5mm f/2.7 on full frame to match it. Note that actual light transmission (exposure) stays the same; only the depth of field characteristic changes.