A/B Test Calculator — Free Online Tool
Calculate statistical significance for A/B test results. Enter visitors and conversions for each variant to see if your results are significant.
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How It Works
Enter the number of visitors and conversions for your control (A) and variant (B). The calculator computes conversion rates, relative improvement, p-value, and tells you whether the result is statistically significant.
Frequently Asked Questions
The default confidence level is 95%, which is the industry standard. You can adjust it to 90% or 99% depending on your needs.
Statistical significance means the difference between your variants is unlikely to be due to random chance. At 95% confidence, there is less than a 5% probability the result occurred by luck.