Bevel is not symmetrical I was trying to model a desk and came across a problem, I can't seem to solve.
I wanted to create a simple bevel.
I used Mesh &gt; Edges &gt; Bevel on a selected edge and got this result


Why is it not symmetrical? How can I make it symmetrical?

For reference, what I actually wanted:
It seems your object has non-uniform scale.  Apply the scale of the object with Ctrl+A > scale to fix this problem.

Beveling with non-uniform scale:


Applying the scale:


Beveling after applying scale:


When you scale an object in object mode, it is not really "applied" to the object's geometry.  I like to think of scaling as a modifier that is always last in the stack, whatever you do in edit mode (or most other places) is as if it was done before the object was scaled.

Check out this question for more uses of applying scale.