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 ZS40 and Panasonic ZS45 side-by-side from the front, back and top in their relative dimensions. Panasonic ZS40 has external dimensions of 111 x 64 x 34 mm (4.37 x 2.52 x 1.34″) and weighs 240 g (0.53 lb / 8.47 oz) (including batteries). Panasonic ZS45 has external dimensions of 108 x 60 x 32 mm (4.25 x 2.36 x 1.26″) and weighs 249 g (0.55 lb / 8.78 oz) (including batteries).
Below you can see the front view size comparison of Panasonic ZS40 and Panasonic ZS45. Panasonic ZS45 is clearly the smaller of the two cameras. Its body is 3mm narrower, 4mm shorter and 2mm thinner than Panasonic ZS40.
Here is the back view size comparison of Panasonic ZS40 and Panasonic ZS45.
Now lets look at the top view comparison of Panasonic ZS40 and Panasonic ZS45.
Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Panasonic ZS40 is 9g lighter than the Panasonic ZS45 but we don't think this will make a significant difference.
Unfortunately neither Panasonic Lumix DMC-ZS40 (Lumix DMC-TZ60) nor Panasonic Lumix DMC-ZS45 (Lumix DMC-TZ57) 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
LCD Screen Size and Features
Panasonic ZS40 and Panasonic ZS45's LCD screens has the same diagonal size of 3".
On the other hand, Panasonic ZS45 features a Tilting screen
where you can change the angle of the screen to make it easier to shoot from waist or over the head levels whereas the Panasonic ZS40 has a fixed type screen which provides less flexibility in shooting positions compared to ZS45.