Perspective doesn’t change
Crop factor alters field of view, not perspective. Camera-to-subject distance sets perspective—sensor size doesn’t.
Distance rules
Crop Factor Calculator
Inputs
Results
Full-frame equivalent:
To match this view on target:
How to use this crop factor calculator
- Pick your current format. Presets cover full frame, APS-C (1.5×/1.6×), and Micro Four Thirds.
- Enter the lens focal length. We compute its 35mm equivalent so you can compare across systems.
- Select a target format. See what focal length matches your framing on that body.
- Remember exposure vs. DoF. f-numbers stay the same for exposure; depth-of-field equivalence scales with crop.
- Use it with adapters. Quick check for how vintage lenses will frame on smaller sensors.
5 Fun Facts about Crop Factor
DoF equivalence scales
To match depth of field, multiply the f-number by the crop (e.g., f/2.8 on MFT ≈ f/5.6 DoF on full frame).
Aperture math
Exposure is unchanged
Crop factor doesn’t change exposure math. f/2.8 is f/2.8 regardless of sensor—only noise and DoF perception shift.
Same light
MFT doubles the view
A 25 mm on Micro Four Thirds frames like a 50 mm on full frame—handy mental check for lens shopping.
2× quick check
Speed boosters reverse it
Focal reducers (speed boosters) shrink the image circle, lowering the effective crop and adding ~1 stop of light.
Optical hacks
About this crop factor calculator
This calculator makes it easy to translate lenses between camera formats. Enter your camera format, focal length, and a target format to see the full-frame equivalent and what lens matches the same field of view on the other system. It’s especially helpful when switching between full frame and APS-C bodies, or when adapting lenses to Micro Four Thirds and needing to know the resulting angle of view.
Everything runs locally in your browser, so no data is uploaded. The results include a short note on whether the target format is tighter or wider, which can guide composition choices and lens selection. The calculation focuses on FOV equivalence; remember that exposure in terms of f-number does not change with crop factor, but depth-of-field equivalence scales with it.
Use this tool when planning lens kits for multi-camera shoots, choosing primes for travel, or explaining to clients why a 25 mm on MFT frames similarly to a 50 mm on full frame. It’s also handy for virtual production or previs when matching real-world lenses to CG cameras that may use different sensor sizes.
Because the calculator is lightweight and client-side, it works offline after loading. Bookmark it with your focal length charts and combine it with the field-of-view and depth-of-field calculators to get a complete picture of how a lens will behave on any given body.