Enter the mean and standard deviations of the positive and negative controls to determine the Z-factor.

## Z Factor Formula

The following formula is used to calculate a Z factor.

Zf = 1 – [ 3*(σp + σn)/|μp – μn| ]

• Where Zf is the Z-factor
• μ are the means of the positive and negative controls
• σ are the standard deviations of the positive and negative controls

## Z Factor Definition

Z factor, which is not the same as a z-score, is a measure of the statistical effect size.

## Z Factor Example

How to calculate a z-factor?

1. First, determine the the means.

Calculate the means of the positive and negative controls.

2. Next, determine the standard deviations.

Calculate the standard deviations of the same positive and negative controls.

3. Finally, calculate the z factor.

Calculate the z factor using the equation above.

## FAQ

What is a z-factor?

A z-factor is a measure of whether the response in a specific assay is large enough to warrant further attention.