How Do You Calculate IC50 From Percent Inhibition?

How Do You Calculate IC50 From Percent Inhibition? To calculate the IC50 value: The inhibitor concentration against the percent activity is plotted ([I]-Activity % graph). Using the linear (y=mx+n) or parabolic (y=ax2+bx+c) equation on this graph for y=50 value x point becomes IC50 value. How is IC50 Dpph calculated? The IC50 value is a parameter