Tools
A/B Test Statistical Significance Calculator
Know when your test has enough data to call a winner, and when to keep running.
A frequentist z-test calculator built for paid media and growth marketers. Enter your visitor and conversion counts for each variation, select your confidence threshold, and get a plain-English result.
X (Input)
Y (Output)
Variation A (Control)
Variation B (Test)
X and Y can represent any two-step funnel. Examples: clicks and leads, impressions and MQLs, sessions and signups, leads and closed-won.
Confidence level
80%: Directional signal. Reasonable to act at early stage or when budget at stake is low.
90%: Strong signal. Appropriate for most paid media optimization decisions.
95% and 99%: Higher confidence threshold. Appropriate when the decision carries significant budget or risk.