Crop Factor
Calculate camera crop factor for any sensor size. Enter sensor type, focal length, and aperture to get 35mm full-frame equivalent focal length and f-stop instantly.
About This Calculator
The Crop Factor Calculator helps photographers understand how their camera sensor size affects lens field of view and depth of field compared to a standard 35mm full-frame camera. Simply select your camera's sensor type, enter your lens focal length and aperture, and the calculator instantly shows the 35mm equivalent values. This is essential when comparing lenses across different camera systems or choosing lenses for crop sensor cameras.
The calculator uses the standard crop factor formula: CF = DFF / Dsensor, where DFF is the diagonal of a full-frame sensor (43.27mm) and Dsensor is the diagonal of your sensor. The equivalent focal length is computed as EFL = FL × CF, and the equivalent aperture as EA = A × CF. The diagonal for each sensor is pre-calculated using the Pythagorean theorem from the sensor width and height dimensions. Supported sensor types include compact camera sensors (1/2.3-inch, 1-inch), Micro Four Thirds, APS-C (Canon and Sony/Nikon variants), APS-H, full-frame, medium format (44×33mm and 645), and large format (4×5-inch).
How Crop Factor Affects Your Photography
Crop factor has three primary effects on your images. First, it changes the effective field of view — a 50mm lens on an APS-C camera gives the same framing as a 75mm lens on full-frame. Second, it affects depth of field — smaller sensors produce deeper depth of field at the same aperture, making it harder to achieve background blur. Third, it impacts low-light performance since smaller sensors typically have more noise at high ISOs. Understanding your camera's crop factor helps you make informed decisions when building your lens kit and setting up shots.
Regional Notes
Crop factor is a universal optical property that does not vary by region. Camera sensor standards are the same worldwide — full-frame is always 36×24mm, APS-C dimensions follow the same manufacturer specifications in IN, US, UK, and EU markets. Focal length is measured in millimeters universally, and aperture f-numbers follow the same international standard. Medium and large format dimensions also use consistent measurements globally. This calculator supports the full range of sensors from compact cameras to large format, covering all major camera systems available worldwide.
Frequently Asked Questions
What is crop factor in photography?
Crop factor is the ratio of a full-frame 35mm sensor's diagonal (43.27mm) to the diagonal of your camera's sensor. It determines how much a lens's field of view is cropped on a smaller sensor. A camera with a crop factor of 1.5x makes a 50mm lens behave like a 75mm lens in terms of field of view on a full-frame camera.
How is crop factor calculated?
Crop factor is calculated by dividing the diagonal length of a full-frame 35mm sensor (43.27mm) by the diagonal length of your camera's sensor. The diagonal is found using the Pythagorean theorem: √(width² + height²). For example, an APS-C sensor with dimensions 23.6×15.6mm has a diagonal of 28.29mm, giving a crop factor of 43.27/28.29 = 1.53x.
How do I calculate 35mm equivalent focal length?
To calculate the 35mm equivalent focal length, multiply your lens focal length by the crop factor of your camera. For example, a 50mm lens on an APS-C camera with a 1.53x crop factor gives an equivalent focal length of 50 × 1.53 = 76.5mm. This means the field of view matches what you would get with a 76.5mm lens on a full-frame camera.
What is the difference between APS-C and full-frame crop factors?
Full-frame cameras have a crop factor of 1.0x (sensor size 36×24mm). APS-C sensors vary by manufacturer: Canon APS-C has a 1.62x crop factor (22.2×14.8mm), while Nikon/Sony APS-C has a 1.53x crop factor (23.6×15.6mm). Micro Four Thirds has a 2.0x crop factor (17.3×13mm), and 1-inch sensors have a 2.7x crop factor (13.2×8.8mm).
Does crop factor affect aperture and depth of field?
Yes, crop factor affects the depth of field equivalently to focal length. A lens at f/2.8 on a crop sensor camera has the same depth of field as a lens at f/2.8 × crop factor on full-frame. For example, f/2.8 on Micro Four Thirds (2x crop) gives depth of field equivalent to f/5.6 on full-frame. This is why larger sensors are preferred for shallow depth of field photography.
What is the crop factor of medium format cameras?
Medium format cameras have sensors larger than full-frame, so their crop factor is less than 1.0x. Common medium format crop factors: 44×33mm sensors (GFX/X1D) have a 0.79x crop factor, and 645 format (56×41.5mm) has a 0.62x crop factor. This means a 50mm lens on a 44×33mm medium format camera behaves like a 39.5mm lens on full-frame — giving a wider field of view.
Can I use full-frame lenses on crop sensor cameras?
Yes, you can use full-frame lenses on crop sensor cameras. The lens projects a large enough image circle to cover the smaller sensor, so there is no vignetting. However, the effective focal length will be multiplied by the crop factor, making the lens appear more telephoto. For example, a 24-70mm lens on a 1.53x crop APS-C camera behaves like a 37-107mm lens.
What is the crop factor of smartphone cameras?
Smartphone cameras typically use very small sensors with high crop factors. A typical 1/2.3-inch smartphone sensor (6.17×4.55mm) has a crop factor of approximately 5.64x. This means a 5mm lens on a smartphone behaves like a 28mm lens on full-frame. The high crop factor is why smartphone cameras struggle with shallow depth of field and low-light performance compared to larger cameras.