Crop Factor Calculator

Crop factor compares a sensor's diagonal size to a full-frame (35mm) sensor. A crop factor of 1.5, for example, means the sensor is 1.5 times smaller in linear dimensions than full frame, which effectively narrows the field of view of any lens you attach.

To compare lenses across formats, multiply the actual focal length by the crop factor to get the "full-frame equivalent" focal length — the focal length that would produce the same field of view on a full-frame camera. This does not change the lens's actual aperture or light-gathering ability, only its angle of view.

Example: a 35mm lens on an APS-C sensor (crop factor 1.5 on Nikon/Sony/Fuji, or 1.6 on Canon) has a full-frame-equivalent field of view of 35 × 1.5 = 52.5mm — noticeably narrower than 35mm would look on a full-frame body.

Crop factor multiplies focal length to get 35mm full-frame equivalent field of view — it does not change physical focal length printed on the lens.

APS-C Canon (1.6×) vs Nikon/Sony/Fuji (1.5×) differ slightly — pick the sensor that matches your body.

Worked example: 35mm lens on 1.5× APS-C → 52.5mm full-frame equivalent FOV.

Depth-of-field equivalence debates aside, crop factor strictly converts field of view — a 35mm lens on 1.5× APS-C frames like 52.5mm on full frame, so you stand in the same spot to match composition, not use a different physical distance. FOV equivalence is not DOF equivalence in all debates — crop factor here converts angle of view, not background blur, for lens shopping.

Speed booster adapters reduce effective crop factor by concentrating the image circle — Metabones-style 0.71× boost on APS-C narrows the crop toward full-frame FOV math; this calculator assumes native lens on native sensor without boosters. Speed boosters reduce effective crop — native MFT math assumes no 0.71× adapter concentrating the image circle onto the sensor.

Micro Four Thirds at 2× crop needs a 17.5 mm lens to match 35 mm full-frame horizontal field of view — handy when comparing travel zoom ranges and deciding whether a second lightweight body is worth the kit weight for hiking photo trips. Olympus and Panasonic shooters use that equivalence daily when matching full-frame framing guides in travel photography forums.