Choose your camera's sensor and lens to see its crop factor and what it equals on full frame (or any other sensor): the focal length for the same view, the f-number for the same depth of field, and the ISO for the same noise.
mm
Printed on your lens
f/
Crop factor of your sensor
1.53×
Equivalent focal length
53.58 mm
Equivalent aperture (depth of field)
f/2.76
Equivalent ISO (noise)
ISO 234
35 mm at f/1.8 on APS-C (Nikon, Fujifilm, Sony) frames like 53.58 mm on Full frame (35 mm), with the depth of field of f/2.76.
The sensors' diagonals differ by 1.53×, so focal length and f-number scale by 1.53 and ISO by 1.53² = 2.34 (1.23 stops of light).
Exposure doesn't change: f/1.8 is still f/1.8 for brightness on any sensor. The equivalent aperture and ISO describe depth of field and noise.
Crop factors (against full frame)
Sensor
Size
Crop
35 mm is like
Full frame (35 mm)
36 × 24 mm
1×
35 mm
APS-C (Nikon, Fujifilm, Sony)
23.5 × 15.7 mm
1.53×
53.58 mm
APS-C (Canon)
22.3 × 14.9 mm
1.61×
56.46 mm
APS-H
27.9 × 18.6 mm
1.29×
45.16 mm
Micro Four Thirds
17.3 × 13 mm
2×
69.98 mm
1-inch type
13.2 × 8.8 mm
2.73×
95.45 mm
1/1.7-inch type
7.6 × 5.7 mm
4.55×
159.4 mm
1/2.3-inch type
6.17 × 4.55 mm
5.64×
197.53 mm
Medium format (Fujifilm GFX)
43.8 × 32.9 mm
0.79×
27.64 mm
Super 35 (film)
24.89 × 18.66 mm
1.39×
48.68 mm
How to work out lens equivalence
Choose your camera's sensor and the one to compare with, usually full frame.
Enter the focal length and f-number printed on your lens, and an ISO.
Read the crop factor and the equivalent focal length, aperture and ISO.
Worked example
A 35 mm f/1.8 lens on a Sony APS-C camera: the crop factor is 1.53, so it frames like 53.58 mm on full frame, with the depth of field of f/2.76. At ISO 100, its noise is like ISO 234 on full frame, 1.23 stops of light apart.
Sensor sizes are typical values for each format; individual cameras vary by a fraction of a millimetre. Everything runs in your browser.
Frequently asked questions
What is crop factor?
How much smaller a sensor's diagonal is than full frame's 43.3 mm. APS-C (Nikon, Sony, Fujifilm) is 1.53×, Canon APS-C 1.61×, Micro Four Thirds 2×, 1-inch type 2.73× and Fujifilm GFX medium format 0.79×.
Does a crop sensor change my lens's focal length?
No, the lens is still the same focal length; the smaller sensor sees a narrower part of the image. That's why a 35 mm lens on APS-C frames like a 53.58 mm lens on full frame: the 35 mm "equivalent" focal length.
What is equivalent aperture?
The f-number that gives the same depth of field (and gathers the same total light) on the other sensor: multiply by the crop factor. 35 mm f/1.8 on APS-C has the depth of field of about 53.58 mm f/2.76 on full frame. Exposure doesn't change: f/1.8 is just as bright on both.
Why is ISO part of equivalence?
A smaller sensor collects less light in total at the same exposure, so its noise at ISO 100 looks like full frame's at about ISO 234 (ISO × crop factor²). It's a guide to noise, not a setting to copy.
What does '26 mm equivalent' on a phone mean?
The phone's real lens is only a few millimetres long, but on its tiny sensor it frames like a 26 mm lens on full frame. Makers quote the 35 mm equivalent so cameras of any sensor size can be compared.
