Transforming multiple objects to have equal dimensions I created several planes scattered around the scene, but I created them individually.

I also extruded several planes to create an expanding curve, without realizing that I was scaling on two axes at the time (for each new plane).
I would have preferred to only scale the 'y' value, but I didn't notice my mistake in ortho view.

Is there a way to change all of their size values to be equal?  Let's say I want them all to be 1cm X 1cm, but they are all currently slightly different sizes. I don't want to change the position or rotation of any of them though. 

Thanks for the help, I'm just getting started in the 3d world.
Just press the Alt key before clicking any of the value text boxes and inserting you values.

That will affect all selected objects instead of just the active one. It will also work for modifiers and most other properties.



Edit

If all your planes belong to the same object you have to separate them before controlling sizes directly, since absolute size control will only work in Object Mode, not Edit Mode.


Enter edit mode in your planes object
Select all with A
Separate all planes with P > Loose Parts
Now exit edit mode
Select all separated plane objects
Move their object center to the center of the geometry so their positions wont change when you change their scale, by pressing Shift + Ctrl + Alt + C > Origin to Geometry
Now you can change size


Don't forget to apply transforms afterwards with Ctrl + A > Scale