qPCR Efficiency Calculator

Calculate qPCR amplification factor and efficiency (%) from standard-curve slope, with quick assay-quality interpretation.

Use this qPCR efficiency calculator to compute amplification factor and efficiency from the slope of your standard curve.

Formula used: Efficiency = -1 + 10^(-1 / Slope). Amplification factor = 10^(-1 / Slope).

For example, slope = -3.35 gives amplification factor = 1.99 and efficiency = 98.84%.

Interpretation guideline: 90-110% efficiency is acceptable; values outside this range indicate assay optimization is needed.

Common optimization steps include 5+ dilution points with triplicates, rerunning outliers, calibrated pipettes, clean template DNA, and primer/probe concentration tuning.

Slope

Amplification factor

qPCR efficiency