APS-C to Full Frame Equivalent Calculator
Use this tool to convert APS-C lens settings into their full frame equivalent for framing and depth of field comparison.
What does APS-C to full frame conversion mean?
When photographers talk about converting APS-C to full frame, they usually mean one of two things: matching field of view (how wide or tight the image looks) and matching depth of field (how blurry the background appears). Because APS-C sensors are smaller than full frame sensors, the same lens behaves differently in framing.
This is where crop factor helps. A typical APS-C camera uses a crop factor around 1.5x or 1.6x. That value tells you how to compare focal length and depth-of-field characteristics to full frame.
How the calculator works
1) Full frame equivalent focal length
To match framing:
Equivalent focal length = APS-C focal length × crop factor
Example: 35mm on a 1.5x APS-C camera gives a framing similar to a 52.5mm lens on full frame.
2) Full frame equivalent aperture (for depth of field)
To match depth of field and subject-background separation:
Equivalent aperture = APS-C aperture × crop factor
Example: f/1.8 on APS-C at 1.5x has similar depth-of-field rendering to about f/2.7 on full frame at equivalent framing.
3) Exposure remains the same
Exposure brightness uses the actual f-number and shutter speed/ISO. So f/1.8 is still f/1.8 for exposure, no matter the sensor size. Equivalence is mainly about visual comparison between formats.
Common APS-C crop factors by brand
- 1.5x: Sony APS-C, Nikon DX, Fujifilm X
- 1.6x: Canon APS-C (most EOS crop bodies)
- 1.52x: Pentax APS-C
If your camera has an unusual crop factor, use the custom option in the calculator.
Practical examples
Street photography setup
If you shoot 23mm f/2 on a 1.5x APS-C camera, your full frame equivalent is about 34.5mm and f/3.0 for depth of field. That’s why many people describe a 23mm APS-C prime as a “35mm full frame equivalent.”
Portrait setup
A 56mm f/1.2 APS-C lens at 1.5x converts to roughly 84mm and f/1.8 equivalent depth of field on full frame. This is one reason APS-C portrait lenses can still deliver beautiful subject separation.
Travel zoom planning
If your APS-C zoom range is 18–55mm at 1.5x, framing compares to 27–82.5mm on full frame. That gives you a fast way to understand what type of scenes your lens can cover.
Why equivalence is useful
- Helps compare lenses between camera systems.
- Makes it easier to switch between APS-C and full frame bodies.
- Improves planning for weddings, portraits, travel, and video work.
- Prevents confusion when reading lens recommendations online.
FAQ
Is APS-C worse than full frame?
Not at all. APS-C cameras can produce excellent image quality. Full frame mainly gives differences in field of view for a given focal length, potential low-light performance, and depth-of-field behavior at equivalent framing.
Do I multiply aperture every time?
Only when comparing depth of field across sensor sizes. For exposure, keep the original aperture value as-is.
Can I use this for video?
Yes. The same crop and field-of-view principles apply in video, though some cameras also apply extra crop in certain modes.
Final tip
Use this calculator as a planning tool, not a rulebook. Lens character, distance to subject, and lighting matter just as much. But for quick APS-C to full frame conversion, these equations are the simplest and most reliable starting point.