ITChart.ChartHeight
ITChart

property ChartHeight: Integer;

Type Library
TeeChartx

Description
Run-time and read only. The ChartHeight property indicates the total height in pixels between the Top and Bottom Chart Axis positions.

It is equal to:

ChartHeight = TChart1.GetChartRect.Bottom - TChart1.GetChartRect.Top

This IS NOT the same as Chart1.Height, because Chart margins, Axis margins, Legend width, etc are first substracted from the Chart vertical size.