For simple high-vacuum problems, hand calculation can yield quick answers to vacuum system design questions. However, for complex networks of vacuum components, computer simulation is the preferred method. Currently, several proprietary, limited-use codes are in use, which has the downside of poor modularity and questionable future applicability in the event that these codes become neglected as computer systems are upgraded. ANSYS is a very popular commercial finite element analysis package, and is frequenty updated. This paper demonstrates how to use ANSYS to perform vacuum calculations.