Lens Crop Factor Calculator
Calculate equivalent focal length and field of view with different sensor sizes.
Compare crop sensor to full frame.
Equivalent Focal Length
Crop factor describes how a camera sensor compares to a 35mm full-frame sensor. Smaller sensors “crop” the image, making lenses appear more telephoto.
Equivalent Focal Length = Actual Focal Length × Crop Factor
Common crop factors:
- Full Frame (35mm): 1.0× (36 × 24mm sensor)
- APS-C (Canon): 1.6× (22.3 × 14.9mm)
- APS-C (Nikon/Sony): 1.5× (23.5 × 15.6mm)
- Micro Four Thirds: 2.0× (17.3 × 13mm)
- 1-inch sensor: 2.7× (13.2 × 8.8mm)
- Smartphone (1/2.55"): ~5.6× (varies by phone)
What changes with crop factor:
- Field of view: Narrower (equivalent to longer lens on full frame)
- Depth of field: Deeper at same framing (sensor is smaller)
- Equivalent aperture: Multiply f-stop by crop factor for DoF comparison
Example: 50mm f/1.8 on APS-C 1.5×:
- Equivalent focal length: 75mm
- Equivalent DoF: ~f/2.7 compared to full frame