This calculator gives the amplification efficiency of a qPCR reaction based on the slope of the standard curve.

Type in the slope of your standard curve to the field corresponding to the orientation of log (DNA copy#) and Ct on your graph.

For a graph where log(DNA copy#) is on the x-axis and Ct on the y-axis:

For a graph where Ct is on the x-axis and log(DNA copy#) on the y-axis: