Crop Factor Calculator

Calculate crop factor and full-frame equivalent focal length for different camera sensors

Calculate Crop Factor

Physical width of the sensor in millimeters

Physical height of the sensor in millimeters

The actual focal length of your lens

Crop Factor Results

1.53x
Crop Factor
76.5mm
Full Frame Equivalent
28.3mm
Sensor Diagonal
65.4%
Field of View vs FF

Formula: Crop Factor = Full Frame Diagonal / Sensor Diagonal

Full Frame: 36mm × 24mm (43.3mm diagonal)

Your Sensor: 23.6mm × 15.6mm (28.3mm diagonal)

Photography Impact

Field of View: Your 50mm lens sees like a 76.5mm lens on full frame
Depth of Field: For equivalent DoF, multiply your f-stop by 1.53
Low Light: Smaller sensors typically have reduced low-light performance
Telephoto Advantage: 1.53x "reach" for wildlife and sports photography

Example Calculation

APS-C Canon Sensor Example

Sensor Size: 22.3mm × 14.9mm

Sensor Diagonal: √(22.3² + 14.9²) = 26.8mm

Full Frame Diagonal: √(36² + 24²) = 43.3mm

Crop Factor: 43.3 ÷ 26.8 = 1.61x

Practical Application

• 50mm lens on APS-C Canon = 80.5mm equivalent on full frame

• f/2.8 on APS-C = f/4.5 equivalent depth of field

• Great for telephoto work, challenging for wide-angle

Common Sensor Sizes

Full Frame1.0x
APS-C Canon1.6x
APS-C Nikon/Sony1.5x
Micro 4/32.0x
1" Sensor2.7x
1/2.3" Sensor5.6x

Photography Tips

Higher crop factors provide more "reach" for telephoto photography

Smaller sensors make wide-angle photography more challenging

Consider crop factor when buying lenses for your camera system

Larger sensors generally perform better in low light

Lens Equivalency

Actual Focal LengthFF Equivalent (1.5x)
14mm21mm
24mm36mm
35mm53mm
50mm75mm
85mm128mm
200mm300mm

Understanding Crop Factor

What is Crop Factor?

Crop factor (also called focal length multiplier) is the ratio between the diagonal of a full-frame (35mm) sensor and the diagonal of your camera's sensor. It tells you how much smaller your sensor is compared to full frame, which affects the field of view of your lenses.

Why Does it Matter?

  • Determines the effective field of view of your lenses
  • Affects depth of field characteristics
  • Influences low-light performance
  • Important for lens selection and composition

Calculation Formula

Crop Factor = Full Frame Diagonal / Sensor Diagonal

Diagonal = √(width² + height²)

  • Full Frame: 36mm × 24mm (43.3mm diagonal)
  • Sensor Diagonal: Calculated from width and height
  • Equivalent Focal Length: Actual focal length × crop factor
  • Field of View: Narrower by the crop factor

Note: Crop factor only affects field of view, not the actual focal length of the lens. The lens physics remain the same.

Practical Applications

Advantages of Crop Sensors

  • • More affordable camera bodies and lenses
  • • Increased "reach" for wildlife and sports photography
  • • Smaller, lighter camera systems
  • • Better depth of field control for macro work

Considerations

  • • Harder to achieve wide-angle shots
  • • Generally reduced low-light performance
  • • Shallower depth of field requires larger apertures
  • • Need to consider crop factor when buying lenses