Caculating tail of a distribution

Question

I have data which follows approximately a normal distribution but with a heavy right tail as shown in the picture below. I have made the plot with seaborn distplot using a gaussian kernel density estimate (hist=True, kde=True, norm_hist=True).

Now I would like to calculate the point where the tail starts. In the picture I have marked this approximately with the red line.

How can I calculate the start point of the tail?