# A/B Test Statistical Significance Calculator

Source: https://www.lucidmedia.co.nz/tools/ab-test-calculator/

Find out if your test results are statistically significant or if you need more data before making a decision.

Quick start: Enter your test results below to see if you have a clear winner or need to keep testing.

## Understanding Statistical Significance

Statistical significance tells you whether your A/B test results are real or just due to random chance. A statistically significant result means you can be confident that the difference between variants is genuine.

### What do the numbers mean?

Confidence Level

How confident you can be in your results. 95% means there's only a 5% chance the results are due to random variation.

P-Value

The probability that your results occurred by chance. Lower is better. Below 0.05 is considered statistically significant.

Sample Size

The number of visitors needed in each variant. Smaller effects require larger sample sizes to detect reliably.

### Common mistakes to avoid

- **Stopping tests too early:** Even if variant B is winning, you need enough data for statistical significance
- **Testing too many things at once:** Test one variable at a time to understand what's driving changes
- **Ignoring external factors:** Holidays, promotions, or seasonal changes can skew results
- **Testing on too small traffic:** Low-traffic sites need longer test durations or larger effect sizes

Want to run more effective A/B tests? Our [CRO services](https://www.lucidmedia.co.nz/services/conversion-rate-optimisation/) can help you design, implement, and analyse tests that drive real business results.

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## Want Help Running Effective A/B Tests?

Our CRO team can design, implement, and analyse tests that deliver real conversion improvements for your business.

Free consultation & quote

Response within 24 hours

No obligation to proceed

[info@lucidmedia.co.nz](mailto:info@lucidmedia.co.nz) [+64 27 582 4369](tel:+64275824369)