Calculated Series Properties Dialog Box, Legend
Select Legend on the Calculated Series Properties dialog box to define the legend text for the specified series.
Options
Do not show this series in a legend
Select this option to hide the text for this series in the legend.Custom legend text
Type a label or an expression to be shown in the legend for this series.Show in legend
Select the legend where the specified series will be displayed. Only applicable if there are multiple legends on the chart.