Indirect Mediation Effect Confidence Interval Calculator

Enter the coefficients for path a and path b along with their standard errors and the significance level (α).

The indirect effect is computed as IE = a × b, and the SE is approximated using the Sobel formula.

Step 1: Enter Parameters

Coefficient a (Path from X to M):

e.g., 0.3

Standard Error of a (SE_a):

e.g., 0.1

Coefficient b (Path from M to Y):

e.g., 0.4

Standard Error of b (SE_b):

e.g., 0.15

Significance Level (α):

e.g., 0.05

How It Works

The indirect effect is computed as: \( IE = a \times b \).

Its standard error is approximated by: \[ SE_{IE} = \sqrt{b^2 \times SE_a^2 + a^2 \times SE_b^2}. \]

The confidence interval is then given by: \[ CI = IE \pm z \times SE_{IE}, \] where \( z \) is the critical value for \(1-\frac{\alpha}{2}\) from the standard normal distribution.

Step 1: Enter Parameters

Results

How It Works