Crop factor & equivalent focal length calculator
What does a 23 mm lens on Fujifilm equal on full frame? Convert focal length and depth-of-field-equivalent aperture between any two sensor sizes and see the field of view in degrees.
A 23 mm lens on APS-C (1.53× crop) frames like a 35 mm lens on full frame. At f/1.4 it gives the depth of field of about f/2.1 there — but exposure stays the same as f/1.4.
- Horizontal field of view
- 54.1°
- Vertical field of view
- 37.5°
- Crop ratio
- 1.53×
- Sensor size
- 23.5 × 15.6 mm
Full-frame equivalent of a 23 mm f/1.4 lens on each format
| Sensor | Focal length | Aperture (DoF) |
|---|---|---|
| Full frame | 23 mm | f/1.4 |
| APS-C (1.5×) | 35 mm | f/2.1 |
| Canon APS-C (1.6×) | 37 mm | f/2.3 |
| Micro Four Thirds | 46 mm | f/2.8 |
| 1-inch | 63 mm | f/3.8 |
| Medium format (44×33) | 18 mm | f/1.1 |
| Phone main camera (1/1.3″) | 81 mm | f/4.9 |
Formulas
Crop factor = 43.27 mm ÷ sensor diagonal. Equivalent focal length = focal length × crop factor. Equivalent aperture (same depth of field and total light at the same framing) = f-number × crop factor. Field of view = 2 × arctan(sensor dimension ÷ (2 × focal length)), for the horizontal, vertical or diagonal dimension.
Sensor sizes compared
| Sensor | Size | Crop factor | Circle of confusion | Area vs full frame |
|---|---|---|---|---|
| Full frame | 36 × 24 mm | 1× | 0.030 mm | 100% |
| APS-C (1.5×) | 23.5 × 15.6 mm | 1.53× | 0.020 mm | 42% |
| Canon APS-C (1.6×) | 22.3 × 14.9 mm | 1.61× | 0.019 mm | 38% |
| Micro Four Thirds | 17.3 × 13 mm | 2× | 0.015 mm | 26% |
| 1-inch | 13.2 × 8.8 mm | 2.73× | 0.011 mm | 13% |
| Medium format (44×33) | 43.8 × 32.9 mm | 0.79× | 0.038 mm | 167% |
| Phone main camera (1/1.3″) | 9.8 × 7.4 mm | 3.52× | 0.009 mm | 8% |
Each format has its own page with depth of field, hyperfocal and astrophotography charts: browse sensor sizes. The crop factor guide covers equivalence in detail.
Crop factor by camera
Exact crop factors from each camera’s published sensor size, with equivalent focal lengths and apertures for the lenses people actually buy for it (all cameras):
- Sony a640023.5 × 15.6 mm · 1.53× crop
- Sony a670023.3 × 15.5 mm · 1.55× crop
- Sony ZV-E1023.5 × 15.6 mm · 1.53× crop
- Canon EOS R5022.3 × 14.9 mm · 1.61× crop
- Canon EOS R1022.3 × 14.9 mm · 1.61× crop
- Nikon Z5023.5 × 15.7 mm · 1.53× crop
- Fujifilm X-T523.5 × 15.6 mm · 1.53× crop
- Panasonic Lumix G9 II17.3 × 13 mm · 2.00× crop
- Sony RX100 series13.2 × 8.8 mm · 2.73× crop
- iPhone 17 Pro main camera≈ 10.0 × 7.5 mm · 3.46× crop
More photography calculators
- Depth of field calculatorNear and far limits of sharpness, with a diagram
- Hyperfocal distance calculatorWhere to focus so everything to infinity is sharp
- Equivalent exposure calculatorTrade aperture, shutter and ISO at the same brightness
- ND filter calculatorLong exposure times for ND8 to ND64000, with a timer
- 500 rule & NPF calculatorLongest exposure for pinpoint stars
Frequently asked questions
What is crop factor?
The ratio between the diagonal of a full-frame sensor (43.3 mm) and the diagonal of another sensor. APS-C is about 1.5× (1.6× for Canon), Micro Four Thirds 2×, 1-inch about 2.7× and 44 × 33 medium format about 0.79×.
How do I calculate equivalent focal length?
Multiply the real focal length by the crop factor: a 35 mm lens on a 1.5× APS-C camera frames like a 52.5 mm lens on full frame, and a 25 mm lens on Micro Four Thirds like a 50 mm lens.
Does crop factor change the aperture?
Not for exposure: f/2 lets through the same light per area on any sensor, so shutter speed and ISO stay the same. For depth of field and total light (which affects noise), multiply the f-number by the crop factor too: 25 mm f/1.8 on Micro Four Thirds looks like 50 mm f/3.6 on full frame.
Does a full-frame lens become longer on a crop camera?
No. A 50 mm lens is always 50 mm; the smaller sensor simply records a smaller part of the image, which looks like a longer lens. That is why crop cameras are popular for wildlife and sports.
What does "26 mm equivalent" mean on a phone?
Phone makers quote full-frame equivalents. A main camera with a 1/1.3-inch sensor has a real focal length of about 7 mm; multiplied by its crop factor of about 3.5, that frames like a 24–26 mm lens on full frame.