Q:

Equal Extrusions?

I am trying to extrude this so all edges are equal distance from their origin edges?

But when I extrude and size them it turns out like this.

How can I get them equal distance apart?

When I change the Offset it doesn't extrude like yours is? Mine goes to the side?

A:

You could use Extrude Along Vetex Normals on the side faces.
It requires a bit of cleanup afterwards

Delete the top faces
Extrude side faces along vertex normals normals Alt + E
Delete extra faces
Bridge the two remaining edgeloops with Bridge Edge Loops

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EDIT Make sure your your mesh is uniformly scaled on all axis, and you have applied scale to the object, otherwise the operation will still be deformed.
Use the operator panel to the left of the 3D screen to introduce accurate distances

