Camera Crop Factor Calculator
Calculate crop factor and full-frame-equivalent focal length from sensor format (or custom diagonal) and lens focal length.
APS-C — Nikon/Sony (1.5x)
Result
Crop Factor
1.50×
Full-Frame Equivalent Focal Length
75.0mm
How to Use the Camera Crop Factor Calculator
Select your camera's sensor format (or enter a custom sensor diagonal in millimeters) and a lens focal length. The calculator finds the crop factor relative to a full-frame sensor and multiplies it by your focal length to get the full-frame-equivalent focal length — the number you'd need on a full-frame camera to get the same field of view.
Crop Factor = 43.3mm / Sensor Diagonal (mm)
Full-Frame Equivalent Focal Length = Lens Focal Length × Crop Factor
Full-Frame Equivalent Focal Length = Lens Focal Length × Crop Factor
Example
A 50mm lens on a Nikon/Sony APS-C camera (1.5x crop factor) gives a full-frame-equivalent field of view of 50 × 1.5 = 75mm — noticeably more zoomed-in than a true 50mm lens on a full-frame body.
Common Use Cases
- Comparing field of view when switching between a crop-sensor and full-frame camera.
- Understanding how a lens will actually frame a shot on your specific camera body.
- Deciding which focal length lens to buy to match a desired full-frame look.
FAQs
- How is this different from the Circle of Confusion Calculator? The Circle of Confusion Calculator is also sensor-format-based, but it's for a completely different purpose — finding the correct circle-of-confusion value used in depth-of-field and hyperfocal distance calculations. This tool is about focal-length equivalence, used for comparing field of view and framing across different sensor sizes.
- Why do Canon and Nikon/Sony APS-C cameras have different crop factors? Canon's APS-C sensors are physically slightly smaller (diagonal ~26.8mm) than Nikon and Sony's APS-C sensors (diagonal ~28.2mm), giving Canon a 1.6x crop factor versus roughly 1.5x for the others, even though both are called "APS-C."
- Does crop factor change the lens's actual focal length? No — the lens's physical focal length and aperture don't change. Crop factor only describes how much of the lens's image circle the smaller sensor captures, which affects field of view (framing) but not the lens's true optical properties like depth of field at a given aperture.