About the Statistical Significance Calculator
Is your A/B test result significant? Two-proportion z-test with p-value, confidence and relative uplift.
Also known as: ab test significance, p value calculator, split test calculator, conversion significance, two proportion z test.
How to use this calculator
- Enter visitors a, conversions a, visitors b, conversions b.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
z = (p̂B − p̂A) / √(p̂(1 − p̂)(1/nA + 1/nB))
Worked example
Using the values pre-filled in the calculator above:
- Visitors A = 5,000
- Conversions A = 200
- Visitors B = 5,000
- Conversions B = 250
the calculator returns:
- Result: Significant (p = 0.0159)
- Conversion A: 4%
- Conversion B: 5%
- Relative uplift: 25%