Focal Length Equivalence (Crop Factor) Calculator
Lens focal length + sensor crop factor -> 35mm-equivalent focal length.
35mm-equivalent focal length
50.0mm
Roughly the field of view of a 50mm lens on a full-frame camera.
Crop factor changes apparent field of view/reach — it does not itself change the lens's physical aperture or depth of field. Any depth-of-field difference people notice comes from the different shooting distance needed to match framing, not from the crop factor directly. For actual depth-of-field math, see the Depth of Field and Hyperfocal Distance calculators.
What is this tool?
Smaller sensors capture a narrower field of view than full frame for the same lens, commonly described via a crop factor multiplier. This tool multiplies focal length by crop factor to get the 35mm-equivalent focal length. Crop factor changes apparent field of view/reach, but doesn't itself change the lens's physical aperture or depth of field — any depth-of-field difference comes from the different shooting distance needed to match framing, not the crop factor directly. For depth-of-field math, see the Depth of Field and Hyperfocal Distance calculators.
How to use it
- Choose a sensor/crop-factor preset, or enter a custom crop factor.
- Enter the lens's actual focal length.
- Read the 35mm-equivalent focal length.
Related photography tools
- Depth of Field CalculatorFocal length, aperture, distance, and sensor size → near/far DOF limits.
- Hyperfocal Distance CalculatorFocal length, aperture, and sensor size → hyperfocal distance and sharp range.
- Exposure Triangle CalculatorChange aperture, shutter, or ISO by stops → equivalent exposure compensations.
- Print Resolution (DPI) CalculatorPixels + print size → DPI with quality flags, or reverse for required pixels.
- ND Filter Shutter Speed CalculatorBase shutter + ND strength → long-exposure shutter speed, or find the ND you need.
- Flash Guide Number CalculatorGN = distance × f-number — solve aperture, distance, or guide number, with ISO scaling.