NodeXL will calculate a variety of graph metrics for you. Some are calculated for each vertex— degree, for example; some are calculated for each of the graph's groups— vertex and edge counts, for example; and some are calculated for the graph as a whole—maximum geodesic distance and graph density, for example.
The calculated graph metrics get inserted into the Vertices, Groups, Group Edges or Overall Metrics worksheets, depending on the metric. For the Vertices, Groups and Group Edges worksheets, the graph metrics get inserted into columns that are normally hidden. Calculating the metrics causes those columns to be shown, but you can hide them again to reduce worksheet clutter.
If you add or remove vertices or edges in the workbook, you have to calculate graph metrics again. The calculated graph metrics do not get updated automatically.
You do not have to show the graph before calculating graph metrics. NodeXL will calculate them even if the Graph Pane is empty.