A/B Test Significance Calculator
Check whether your A/B test result is statistically significant. This free online business & marketing calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
The tool computes each variant's conversion rate and the relative uplift, then runs a two-proportion z-test. The z-score is the difference in rates divided by its pooled standard error; a magnitude above 1.96 indicates significance at the common 95% confidence level (p < 0.05).
Worked Example
Below is a worked example using the calculator's default values. The same numbers are pre-filled in the form above so you can press Calculate and see the result without typing anything.
Inputs used:
- Variant A — Visitors: 1000
- Variant A — Conversions: 100
- Variant B — Visitors: 1000
- Variant B — Conversions: 130
With these inputs, the calculator computes the metrics shown in the Results panel. Change any value and press Calculate again to see how the result responds — the live widget and the chart both update instantly.
Frequently Asked Questions
What does the A/B Test Significance Calculator compute?
The A/B Test Significance Calculator takes 4 input values and returns 4 results. Compare two variants in an A/B test and check whether the difference in conversion rate is statistically significant using a two-proportion z-test.
Is my data sent to a server?
No. The A/B Test Significance Calculator runs entirely in your browser using static JavaScript. Your inputs are never transmitted to CalculatorHive or any third party, and nothing is stored after you close the page.
Is this calculator free to use?
Yes. Every calculator on CalculatorHive is completely free. There is no signup, no paywall, and no usage limit. The site is supported by display advertising and affiliate partnerships, which are clearly labeled.
How accurate is the result?
The math is mathematically exact for the inputs you provide. Real-world accuracy depends on how accurately your inputs reflect the real situation — defaults are typical values, not guarantees.