Focal Length Equivalent Calculator
Convert camera focal lengths between sensor sizes including full frame, APS-C, Micro Four Thirds, and more.
Focal length equivalence lets you compare the field of view of lenses across different camera sensor sizes. A 50mm lens on a crop sensor camera gives a different field of view than 50mm on full frame.
The formula:
Equivalent Focal Length = Actual Focal Length x Crop Factor
Common sensor sizes and crop factors:
| Sensor Format | Sensor Size | Crop Factor |
|---|---|---|
| Full Frame (35mm) | 36 x 24 mm | 1.0x |
| APS-C (Canon) | 22.3 x 14.9 mm | 1.6x |
| APS-C (Nikon/Sony) | 23.5 x 15.6 mm | 1.5x |
| Micro Four Thirds | 17.3 x 13 mm | 2.0x |
| 1-inch sensor | 13.2 x 8.8 mm | 2.7x |
| Medium Format | 43.8 x 32.9 mm | 0.79x |
| 1/2.3 inch (phone) | 6.17 x 4.55 mm | 5.6x |
What this means in practice:
- A 50mm lens on APS-C (1.5x crop) gives the same field of view as 75mm on full frame.
- A 25mm lens on Micro Four Thirds (2.0x crop) equals 50mm on full frame.
- Full frame is the reference standard because 35mm film was the dominant format for decades.
Depth of field also changes: Smaller sensors produce more depth of field at the same equivalent focal length and aperture. To match the depth of field, divide the aperture by the crop factor too.
Common full-frame equivalents for portrait photography: 85mm. For landscapes: 16-35mm. For street photography: 35-50mm.