Camera Sensor Size Table
| Format | Diagonal (mm) | Width (mm) | Height (mm) | Aspect |
|---|---|---|---|---|
| 1/2.5" (phone/compact) | 7.18 | 5.76 | 4.29 | 4:3 |
| 1/2.3" (compact, Pentax Q) | 7.66 | 6.17 | 4.55 | 4:3 |
| 1/1.7" (Canon G10 class) | 9.50 | 7.60 | 5.70 | 4:3 |
| 2/3" (Nokia 1020, Fuji class) | 11.00 | 8.80 | 6.60 | 4:3 |
| 1" (Nikon CX, Sony RX100) | 15.86 | 13.20 | 8.80 | 3:2 |
| Four Thirds / Micro Four Thirds | 21.60 | 17.30 | 13.00 | 4:3 |
| APS-C (Sony/Nikon/Fuji DX) | 28.2–28.4 | 23.6–23.7 | 15.60 | 3:2 |
| Canon APS-H (retired) | 33.50 | 27.90 | 18.60 | 3:2 |
| 35mm film full-frame | 43.1–43.3 | 35.8–36 | 23.9–24 | 3:2 |
| Medium format (Hasselblad H5D-60c class) | 67.08 | 53.70 | 40.20 | 4:3 |
Sensor size is the spec sheet's quiet king: two cameras with the same 24 megapixels behave nothing alike if one sensor is 1/2.3-inch and the other is full frame, because the bigger chip gives every pixel more area to catch light. The chart lines up the whole family - the tiny phone-class chips, the 1-inch type that revived compacts, Four Thirds, APS-C in its many flavors, the retired APS-H, 35mm full frame, and medium format - with true millimeter dimensions instead of marketing fractions.
Two conventions explain most of the confusion. The inch designations are lies by tradition: a 1-inch sensor is 13.2 mm wide, not 25.4, because the naming inherits from 1950s vidicon camera tubes whose glass faceplates exceeded their active area - so the fraction column is a category name, not a measurement. And crop factor is simply full frame's diagonal (about 43.3 mm) divided by your sensor's diagonal, which is why a 50mm lens on APS-C behaves like a 75mm and why wildlife shooters happily pay the crop.
How to use
- Compare sensors by diagonal, not by name: the inch fractions sort categories but hide size gaps - 1/2.3-inch (7.7 mm diagonal) to 1-inch (15.9 mm) is over a doubling of sensor area per megapixel, and full frame is roughly seventeen times the light-collecting area of a 1/2.3 chip.
- Compute crop factor from the chart's diagonal column: divide 43.3 by the diagonal - Four Thirds crops at 2x, APS-C at about 1.5x (1.6x for Canon), and medium format crops below 0.8x - then multiply any lens focal length to get its full-frame-equivalent field of view.
- Match the format to the job: phones and compacts own portability with tiny sensors and computational rescue, Four Thirds and APS-C balance size against depth-of-field control for travel and wildlife, and full frame or medium format earn their bulk in low light, portraits at f/1.4, and studio work where per-pixel quality is the product.
Frequently asked questions
Why is a 1-inch sensor not one inch wide?
Because the inch naming is a fossil from television camera tubes. In the 1950s-80s, vidicon tubes came in 1-inch, 2/3-inch and half-inch sizes measured by the outside diameter of the glass envelope - and the light-sensitive target inside was always smaller, about 60-70 percent of the nominal number. When CCD and CMOS sensors replaced tubes, manufacturers kept the tube names so buyers could compare fields of view, which is why the chart shows a 1-inch sensor at 13.2 by 8.8 mm. The name is a category; the millimeters are the truth.
What does crop factor do to my lenses?
It narrows the field of view by the diagonal ratio. A full frame sensor sees what a 35mm film camera saw; an APS-C sensor (diagonal about 28.3 mm) sees a tighter 43.3/28.3 = 1.53x slice of the same scene, so a 50mm lens frames like a 76mm. Nothing about the lens changes - the light circle still covers - but effective reach improves, which is why bird and sports photographers often prefer crop bodies, while landscape shooters pay for full frame to get the wide end back.
Is a bigger sensor always better?
Only per pixel of light. A larger sensor gathers more total photons, so at the same exposure it needs less amplification, which shows up as cleaner shadows and better color in dim rooms - the physics is real and the chart's area ratios are the size of the effect. The costs are size, weight and price: bigger sensors need bigger, more expensive lenses to cover them, and depth of field gets shallower, which is flattering for portraits but a liability for macro and landscape work where photographers stop down anyway. Choose by the light you shoot in, not by the spec sheet's top row.
Why do phones use such tiny sensors?
Because a phone must stay flat. Sensor diagonal drives optics: to cover a full frame sensor at a useful focal length, the lens needs tens of millimeters of flange distance and image circle - impossible inside an 8 mm body. Phone cameras fit 1/2.5-inch to 1-inch chips behind lenses the size of a lentil and recover quality with computational photography: multi-frame stacking replaces the photon advantage a big sensor has. The chart's top rows are the battleground where per-pixel physics and software noise reduction now trade blows.