Size and weight is a big decision factor when you are trying to find the ideal camera for your needs.
In this section, We are going to illustrate Panasonic G9 and Nikon P520 side-by-side from the front, back and top in their relative dimensions. Panasonic G9 has external dimensions of 137 x 97 x 92 mm (5.39 x 3.82 x 3.62″) and weighs 658 g (1.45 lb / 23.21 oz) (including batteries). Nikon P520 has external dimensions of 125 x 84 x 102 mm (4.92 x 3.31 x 4.02″) and weighs 550 g (1.21 lb / 19.40 oz) (including batteries).
Below you can see the front view size comparison of Panasonic G9 and Nikon P520. Nikon P520 is 12mm narrower and 13mm shorter than Panasonic G9 but it is also 10mm thicker. As you can tell, actually this is not a fair size comparison since Nikon P520 has a built-in lens but Panasonic G9 doesn't. Once you put a lens on G9, its thickness will increase significantly.
Here is the back view size comparison of Panasonic G9 and Nikon P520.
Now lets look at the top view comparison of Panasonic G9 and Nikon P520.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Nikon P520 is significantly lighter (108g ) than the Panasonic G9 which may become a big advantage especially on long walking trips.
Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on G9, the total kit will weigh much higher.
With its weather sealed body, we believe that G9 has a big advantage over P520 which doesn't provide any kind of environmental sealing.
LCD Screen Size and Features
Nikon P520's 3.20" LCD screen is slightly larger than Panasonic G9's 3" screen.