Already have a sample size? Recover the power your study actually achieved to detect a given effect — essential for reviews, rebuttals, and interpreting null results.
Study inputs
Group 2 is derived from the allocation ratio
1 = equal groups
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Achieved power (1 − β)
Enter your study details to recover its power.
Formula used
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Reading the result. Power is the probability of detecting the specified effect if it is real. Below ~80% a non-significant result is hard to interpret — absence of evidence, not evidence of absence. Normal-approximation method; confirm edge cases with a statistician or book a consult.