See whether your A/B test result is real
Enter the visitors and conversions for two versions of a page, and this calculator works out whether the difference between them is large enough to trust, or still likely down to chance.
A/B Test Significance Calculator: find out if your result is real or just noise
Running two versions of a page or an email and watching one pull ahead feels like progress. This calculator takes the numbers from both versions of a test and works out how likely it is that the gap you saw would show up even if neither version was actually better. It's built for anyone comparing two headlines, two subject lines or two landing pages who wants to know whether to trust a result before changing anything on the strength of it.
-
Enter your test numbers
Enter the number of visitors or emails each version reached and how many converted, clicked or signed up.
-
Check the significance result
Read the result to see whether the gap between your two versions is large enough, given the numbers involved, to be more than chance.
-
Decide what to do next
Weigh the result against your sample size and how long the test ran before deciding to keep, extend or drop the change.
A/B test significance calculator
Enter the visitor and conversion numbers from your two versions and this tool works out the p-value, telling you how likely it is that the difference between them is real. It's built for anyone running a test on a landing page, email subject line or checkout flow who wants a clear answer before deciding which version to keep.
Test Data
Results
Enter your test data and click Calculate to see your results here.
A result can be statistically significant and still too small to matter for your business, so weigh the p-value alongside the size of the uplift and what it would actually take to act on it. This tool can give you a misleading answer if your sample is small or your test ran for too short a time, so treat the output as a steer.
See whether your test result is real, or just noise
An A/B test tells you which version of a page or email did better, but not whether the gap between them is big enough to trust. This calculator takes the visitor and conversion counts from each version and works out whether the difference holds up statistically, or whether it could just as easily be chance. It's built for a landing page or subject line test with a modest number of visitors. A result that looks promising with too few visitors is still a guess.
No sign-up needed · Free to use · Works on any device
Popular Tools
Promotion Channel Prioritiser
Answer a few questions about your site, budget, and time — get a ranked shortlist of the promotion channels most likely to work for your specific situation.
Prioritiser ToolContent Distribution Planner
An interactive Content Distribution Planner, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Content Distribution Planner | Tools
Website Launch Promotion Checklist Scorer
An interactive Website Launch Promotion Checklist Scorer, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Website Launch Promotion Checklist Scorer | ToolsLaunch Promotion Countdown Planner
An interactive Launch Promotion Countdown Planner, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Launch Promotion Countdown Planner | Tools
Organic Traffic Growth Estimator
An interactive Organic Traffic Growth Estimator, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Organic Traffic Growth Estimator | ToolsPromotion Tactics Reference Table
An interactive Promotion Tactics Reference Table, free to run in the browser. The companion guide sets out the method behind it, so you can check the working.
Promotion Tactics Reference Table | Tools