Correlation Test Sample Size Calculator
ProCalculate the sample size needed to test whether a Pearson correlation coefficient differs from a null value.
Study Parameters
Results
Required Sample Size
85
Achieved Power
80.0%
Effect Size
0.300
Method: Two-sided correlation test (Fisher z)
Fisher z(r)0.310
Fisher z(r0)0.000
|r - r0|0.300
- •Bivariate normal distribution
- •Fisher z-transformation for variance stabilisation
- •Two-sided hypothesis test
- •Null correlation rho_0 = 0
Formula
n = [(z_{alpha/2} + z_beta) / (arctanh(r) - arctanh(r0))]^2 + 3
References
- Cohen J (1988). Statistical Power Analysis for the Behavioral Sciences, 2nd ed. Erlbaum.
- Fisher RA (1921). On the 'probable error' of a coefficient of correlation deduced from a small sample. Metron, 1, 3-32.