Minimum Detectable Effect Calculator

Estimate the smallest conversion-rate lift an A/B test plan can reliably detect.

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Minimum detectable effect

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Uses total sample size and visible split.

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Solve d where power(pA, pB, nA, nB, alpha) equals requested power How?

How this is calculated

This calculator solves the two-independent-proportions z-test power equation. It uses pooled variance under the null, non-pooled variance under the alternative, and the visible traffic split to derive A and B sample sizes.

Formula: Solve d where power(pA, pB, nA, nB, alpha) equals requested power

Sources

  1. statsmodels power_proportions_2indep. statsmodels. Retrieved .
  2. statsmodels samplesize_proportions_2indep_onetail. statsmodels. Retrieved .

Method last reviewed