Vaguely, although you can't do it directly with the plotted line.. .. .<thinks back to A level Maths>. .. .Gradient of curve at a point = dy/dx .. .. .You know that the gradient can be expressed as the angle between the x-axis and the point on the curve. Simple Trigonometry tells you that:. .. .Tan A = Opposite / Adjacent. .(where A is the Gradient). .Therefore:. .A = ArcTan (Opposite / Adjacent). .. .which in our case is :. .. .Gradient = ArcTan (Y/X) . .. .Now, remember I said that gradient = dY / dX ?. .That says that for a very small change in the values of Y and X this is true.. .. .So you need to have 2 points very close to one another on your curve to be able to calculate the gradient. Assuming you have 2 such points in your data, called X1,Y1 and X2,Y2:. .. .Gradient = ArcTan ((X2-X1) / (Y2-Y1)) in degrees.. .. .So find the ARCTAN function on the Excel menu and find the 2 coordinates you need. . .. .Hope this helps