Crop Factor Calculator
Pick your camera's sensor and lens to see the crop factor, the full-frame (35 mm) equivalent focal length and aperture, and the field of view. Compare any two sensors to find the lens that gives the same picture on another camera.
How to use the Crop Factor Calculator
- Choose your camera's sensor or enter a custom width and height.
- Enter the lens focal length and aperture printed on the lens.
- Read the crop factor and the full-frame equivalent focal length and aperture.
- Pick another sensor to compare and see which lens gives the same view on it.
- Check the table for equivalent settings on every common sensor size.
Crop factor formula
Crop factor = 43.27 mm ÷ sensor diagonal, where diagonal = √(width² + height²)
- Equivalent focal length = focal length × crop factor
- Equivalent aperture (depth of field and total light) = f-number × crop factor
- Field of view = 2 × arctan(sensor dimension ÷ (2 × focal length))
- Light difference in stops = 2 × log₂(crop factor)
Example: Micro Four Thirds is 17.3 × 13 mm, so the diagonal is √(17.3² + 13²) = 21.64 mm and the crop factor is 43.27 ÷ 21.64 = 2.0. A 25 mm f/1.4 lens frames like a 50 mm lens on full frame and gives depth of field like f/2.8.
Sensor size and crop factor chart
| Sensor | Size | Diagonal | Crop factor | 50 mm looks like |
|---|---|---|---|---|
| Medium format 53.4 × 40 mm | 53.4 × 40.0 mm | 66.7 mm | 0.65× | 32 mm |
| Medium format 44 × 33 mm | 43.8 × 32.9 mm | 54.8 mm | 0.79× | 39 mm |
| Full frame / 35 mm (36 × 24) | 36.0 × 24.0 mm | 43.3 mm | 1.00× | 50 mm |
| APS-H (27.9 × 18.6) | 27.9 × 18.6 mm | 33.5 mm | 1.29× | 65 mm |
| APS-C Nikon, Sony, Fuji (23.5 × 15.6) | 23.5 × 15.6 mm | 28.2 mm | 1.53× | 77 mm |
| APS-C Canon (22.3 × 14.9) | 22.3 × 14.9 mm | 26.8 mm | 1.61× | 81 mm |
| Micro Four Thirds (17.3 × 13) | 17.3 × 13.0 mm | 21.6 mm | 2.00× | 100 mm |
| 1-inch type (13.2 × 8.8) | 13.2 × 8.8 mm | 15.9 mm | 2.73× | 136 mm |
| 2/3-inch (8.8 × 6.6) | 8.8 × 6.6 mm | 11.0 mm | 3.93× | 197 mm |
| 1/1.7-inch (7.6 × 5.7) | 7.6 × 5.7 mm | 9.5 mm | 4.55× | 228 mm |
| 1/2.3-inch (6.17 × 4.55) | 6.17 × 4.55 mm | 7.7 mm | 5.64× | 282 mm |
| 1/3-inch (4.8 × 3.6) | 4.8 × 3.6 mm | 6.0 mm | 7.21× | 361 mm |
Exact sensor dimensions differ slightly between camera models, so the crop factor of your camera may vary in the second decimal place. Check your camera's specifications and use a custom size for exact values.
Frequently asked questions
What is crop factor?
Crop factor is the ratio of the full-frame (36 × 24 mm) sensor diagonal, 43.27 mm, to the diagonal of another sensor. An APS-C sensor of 23.5 × 15.6 mm has a 28.2 mm diagonal, so its crop factor is 43.27 ÷ 28.2 ≈ 1.53.
How do I calculate the equivalent focal length?
Multiply the real focal length by the crop factor. A 50 mm lens on a 1.5× APS-C camera gives the same field of view as a 75 mm lens on full frame, and a 25 mm lens on Micro Four Thirds (2×) looks like 50 mm.
Does crop factor change the aperture?
The f-number for exposure does not change: f/1.8 gives the same brightness per area on any sensor. But for the same framing, depth of field and total light gathered match a full-frame lens at f-number × crop factor, so 25 mm f/1.4 on Micro Four Thirds behaves like 50 mm f/2.8 on full frame for background blur.
What are the crop factors of common sensors?
Medium format 44 × 33 mm is about 0.79×, full frame 1.0×, APS-H about 1.3×, APS-C 1.5× (Nikon, Sony, Fujifilm) or 1.6× (Canon), Micro Four Thirds 2.0×, 1-inch type 2.7× and 1/2.3-inch about 5.6×.
Does a crop sensor make my lens longer?
No. The lens's focal length and magnification stay the same; the smaller sensor simply records a smaller part of the image circle. The result looks like a longer lens on full frame because the field of view is narrower.
Why are small sensor sizes called 1-inch or 1/2.3-inch?
These names come from old video camera tubes and refer to the outside diameter of a tube, not the sensor itself. A 1-inch type sensor actually measures about 13.2 × 8.8 mm, with a 16 mm diagonal.