Free Statistical Tools
Free statistical tools for marketers and analysts running real experiments. No email gate, no paywalls — use them at any stage of your testing process.
- A/B Test Statistical Significance Calculator Calculate whether your A/B test results are statistically significant using a chi-square test. Supports one-tailed and two-tailed testing with up to 3 variants.
- Chi-Square Test Calculator for CRO Test whether conversion rates differ significantly across multiple groups — traffic sources, page variants, segments, and more. Fixed at 95% confidence.
- Minimum Detectable Effect (MDE) Calculator Find the smallest effect size your A/B test can reliably detect given your sample size, baseline rate, and desired statistical power.
- Sample Size Calculator for A/B Testing Calculate the minimum sample size needed per variation before launching your A/B test, based on your baseline conversion rate and MDE.
- Welch's T-Test Calculator Compare the means of two independent groups with unequal variances. Ideal for revenue-per-visitor, average order value, and other continuous metrics.
Also explore: Articles on CRO and statistical testing →