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 Olympus SZ-30MR and Pentax Q side-by-side from the front, back and top in their relative dimensions. Olympus SZ-30MR has external dimensions of 106 x 69 x 40 mm (4.17 x 2.72 x 1.57″) and weighs 226 g (0.50 lb / 7.97 oz) (including batteries). Pentax Q has external dimensions of 98 x 57 x 31 mm (3.86 x 2.24 x 1.22″) and weighs 180 g (0.40 lb / 6.35 oz) (including batteries).
Below you can see the front view size comparison of Olympus SZ-30MR and Pentax Q. Pentax Q is clearly the smaller of the two cameras. Its body is 8mm narrower, 12mm shorter and 9mm thinner than Olympus SZ-30MR. As you can tell, actually this is not a fair size comparison since Olympus SZ-30MR has a built-in lens but Pentax Q doesn't. Once you put a lens on Q, its thickness will increase significantly.
Now lets look at the top view comparison of Olympus SZ-30MR and Pentax Q.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Pentax Q is significantly lighter (46g ) than the Olympus SZ-30MR 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 Q, the total kit will weigh much higher.
Unfortunately neither Olympus SZ-30MR nor Pentax Q provides any type of weather sealing in their body, so you have to give extra care especially when you are shooting outdoors. If weather sealing is a must-have feature for you, check these sections: Top Compact Cameras with Weather Sealing Top Mirrorless Cameras with Weather Sealing
LCD Screen Size and Features
Olympus SZ-30MR and Pentax Q's LCD screens has the same diagonal size of 3".
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.