AB Test Calculator
Test whether version B really beat version A using conversions and visitors (two-proportion z-test).
Compare Your Options And Get Clear Answers
Test whether version B really beat version A using conversions and visitors (two-proportion z-test).
AB Test Estimator
Enter your numbers below for an instant estimate.
How It Works
Key concepts behind this calculator
Enter Values
Fill in each field with your own numbers.
Calculate
Results update as you change the inputs.
Review
Read the breakdown and the explanation.
Adjust
Change values to compare scenarios.
AB Quick Guide
Typical values for reference.
| Visitors A | A conv | B conv | p-value |
|---|---|---|---|
| 5000 | 250 | 260 | 0.6494 |
| 5000 | 250 | 290 | 0.0768 |
| 2000 | 100 | 130 | 0.0416 |
| 10000 | 500 | 560 | 0.0583 |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
AB Test Calculator FAQ
Answers to common questions about this calculator.
The chance of a gap this large if there is truly no difference.
Enough to detect your smallest useful lift; decide before testing.
z = (pB – pA) / sqrt(p(1-p)(1/nA + 1/nB)).
It is an estimate based on the inputs you enter. Check real quotes, labels or official guidance for important decisions.