Question: For a two terminal current sensing shunt resistor with a layout that deviates from the symmetric Kelvin layout, what results should be expected? 

For example, with this layout, what result would be expected on the sense leads when the resistor is subject to a 3A current?

[![enter image description here](https://i.stack.imgur.com/NLRhF.png)](https://i.stack.imgur.com/NLRhF.png)

Answer: 
You should take the opportunity to route your sense traces so that they are as close to the same length and symmetrical as possible. Here is a mockup of what I am suggesting.

[![enter image description here](https://i.stack.imgur.com/6NDf5.png)](https://i.stack.imgur.com/6NDf5.png)

You almost want to consider the routing of these sense lines as a controlled impedance pair. The goal to be that both lines share the same common mode voltage coupling from other circuits and external influences.
You almost have perfect symmetry.

I'd flatten that lower right region just to right of "4", and achieve total balance.

To simulate the effects, build a grid of 2\_D resistors that includes that 45\_degree piece; use 0.000498 ohms (that is 500 microOhms) per square.

Then you need to include the 3rd dimension of the resistor's solder terminal.