Ladder logic is a graphical language widely used to program Programmable Logic Controllers (PLCs). PLCs are found at the heart of most industrial control systems used in automation because they are robust, they are relatively easy to program and because they are a proven technology. However there is currently no means to measure the intrinsic properties and qualities of the code produced. This paper details a method for creating tools to calculate software metrics for ladder logic, specifically Rockwell Automation's implementation of ladder logic for its ControlLogix family of PLCs, Import-Export language version 2.6. Results obtained from these tools are briefly discussed also.