“If there's a single factor that predicts the quality of the photos you'll get from a camera, a single letter grade that lets you compare cameras, it's this: the sensor size” (David Pogue, “Help Crack the Sensor-Size Code”).

Using our sensor size calculator, you can easily convert the unfriendly measurements that digital camera manufacturers supply (like ratios or millimeters per side) to a simple diagonal measurement in inches. The larger this measurement, the higher quality of photos you're likely to get from the camera.


Compare the sensor sizes of best-selling cameras here without having to find and calculate them yourself.

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Commonly used for smaller cameras like point-and-shoot models.

Enter sensor ratio: /

Commonly used for larger cameras like SLR models.

Enter sensor ratio: x

Sensor size in inches diagonally:

Interested in learning more about digital photography? Check out David Pogue's Digital Photography: The Missing Manual.