Size and weight are big decision factors when you are trying to find the ideal camera for your needs.
In this section, we are going to illustrate the Casio EX-Z450 and Canon SD940 IS side-by-side from the front, back and top in their relative dimensions. Casio EX-Z450 has external dimensions of 81 x 56 x 21 mm (3.19 x 2.2 x 0.83″) and weighs 128 g (0.28 lb / 4.52 oz) (including batteries). Canon SD940 IS has external dimensions of 89 x 55 x 20 mm (3.5 x 2.17 x 0.79″) and weighs 120 g (0.26 lb / 4.23 oz) (including batteries).
Below you can see the front-view size comparison of the Casio EX-Z450 and the Canon SD940 IS. Canon SD940 IS is 1mm shorter and 1mm thinner than Casio EX-Z450 but it is also 8mm wider.
Here is the back view size comparison of the Casio EX-Z450 and Canon SD940 IS.
Weight is another important factor, especially when deciding on a camera that you want to carry with you all day.
Canon SD940 IS is 8g lighter than the Casio EX-Z450 but we don't think this will make a significant difference.
Weather Sealing
Unfortunately neither the Casio Exilim EX-Z450 nor Canon PowerShot SD940 IS / Digital IXUS 120 IS provides any type of weather sealing in their bodies, 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
LCD Screen Size and Features
Casio EX-Z450's 3.00" LCD screen is slightly larger than Canon SD940 IS's 2.7" screen.
Unfortunately, both cameras has fixed screens so they don't tilt or flip in directions.