35mm Equivalent Focal Length
Convert a lens focal length to its full-frame (35mm) equivalent using crop factor.
About 35mm Equivalent Focal Length
A smaller sensor crops the image circle, so a lens appears longer than it would on full frame by the crop factor. Crop factor lets photographers compare fields of view across sensor sizes and choose the right lens for the desired framing.
Formula
35mm Equivalent Focal Length
Equiv focal length = focal length x crop factor
- crop factor
- Sensor size relative to full frame (1.5 = APS-C)
Worked example
With the default values below, 35mm Equivalent Focal Length returns Full-Frame Equivalent of 75.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Focal lengthminimum 1
- 50
- Crop factorminimum 0.5
- 1.5
Results
- Full-Frame Equivalent
- 75.0 mm
- Field of View vs Full Frame
- 66.67%
Step by step
- 1Values used
- 235mm Equivalent Focal Length
- 3Full-Frame Equivalent= 75.0 mm
- 4Field of View vs Full Frame= 66.67
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is 35mm Equivalent Focal Length calculated?
Equiv focal length = focal length x crop factor A smaller sensor crops the image circle, so a lens appears longer than it would on full frame by the crop factor.
Why does 35mm Equivalent Focal Length matter?
Crop factor lets photographers compare fields of view across sensor sizes and choose the right lens for the desired framing.
What values do I need to enter?
This calculator takes 2 inputs: Focal length, Crop factor. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.