How to change dimensions of an object proportionally?

I have a situation.
I need to change the 3 dimensions of an object, but only by changing one dimension.

That is, if the object has the following dimensions:
High: 2 units (Z)
Width: 0.5 units (Y)
Depth: 0.1 units (X)

When I change the height of 2 units to 3 units, then the other width dimensions (Y) and depth (X) should automatically change to 0.75 and 0.15 respectively.

I do this using the S key:

  1. I press the S key
  2. I press the = key
  3. After Income Division 3/2. 3 is the new dimension and 2 above.

But I would like to know. If there is a better way to do so through the properties panel (N key).
The options in the properties panel (N key), when I change the height of 2 units to 3 units, the width and depth do not change.


One way is to copy Z scale value and paste it to X and Y scale values.
Ctrl+C and Ctrl+V, just move mouse cursor to top of Z scale and copy and then same thing to X and Y with paste.

Right. I know that.
But why do they put locks on the right of the input boxes?

My guess is that the locks are there for animation purposes (or simply moving objects). The easiest example is a regular door; in real life, they can only rotate about one axis (along the hinges). So in Blender, locking the other two axis allows you to open/close the door simply by pressing ‘r’; and without worrying about your view direction, or needing to specify a rotation axis. Another example; if you’re arranging furniture in a house, and need all the furniture to remain on the floor (lock z position) and parallel to it (lock x and y rotation).