Financie

Kalkulačka A/B testovania

A/B Test Statistical Significance

VARIANT A (Control)

Visitors

Konverzie

VARIANT B (Test)

Visitors

Konverzie

What is A/B Test Calculator?

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A/B testing (split testing) compares two versions of a web page, email, or other element to determine which performs better. Statistical significance testing ensures the observed difference is not due to random chance. A result at 95% confidence means there is only a 5% probability the difference occurred by chance.

DigiCalcs delivers precision-engineered tools for engineers and STEM professionals.

Vzorec

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f(x)Calculate conversion rates for each variant: rate = conversions / visitors

How to A/B Test Calculator

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1Calculate conversion rates for each variant: rate = conversions / visitors
2Compute the pooled proportion: p_pool = (cA + cB) / (vA + vB)
3Calculate the standard error: SE = sqrt(p_pool × (1 − p_pool) × (1/nA + 1/nB))
4Z-score: z = (rateB − rateA) / SE
5If |z| ≥ 1.96, the result is significant at 95% confidence (two-tailed)

Worked Examples

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Example 1

Given:A: 1,000 visitors, 50 conversions. B: 1,000 visitors, 70 conversions

Výsledok:Z = 2.08 — Significant at 96.2%

Relative lift: +40%. B is the winner.

Example 2

Given:A: 200 visitors, 10 conversions. B: 200 visitors, 13 conversions

Výsledok:Not significant — need more traffic

Small sample size means high uncertainty

Real-World Applications

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Academic homework and exam preparation

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Engineering and architecture calculations

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Everyday measurement tasks around the home

Common Confidence Levels and Z-Scores

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Confidence Level	Z-Score (two-tailed)	Meaning
90%	1.645	10% chance of false positive
95%	1.960	5% chance — industry standard
99%	2.576	1% chance — high confidence
99.9%	3.291	Very high confidence

Frequently Asked Questions

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What is Ab Test Calc?

How accurate is the Ab Test Calc calculator?

The calculator uses the standard published formula for ab test calc. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.

What units does the Ab Test Calc calculator use?

This calculator works with inches, percentages. You can enter values in the units shown — the calculator handles all conversions internally.

What formula does the Ab Test Calc calculator use?

The core formula is: Calculate conversion rates for each variant: rate = conversions / visitors. Each step in the calculation is shown so you can verify the result manually.

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Pro Tip

Run tests until you reach the required sample size — peeking at results early and stopping when you see significance inflates false positive rates. Use a sample size calculator before starting the test.

References

Len na informačné účely. Tento nástroj nepredstavuje finančné poradenstvo. Pred investičnými alebo finančnými rozhodnutiami sa poraďte s kvalifikovaným finančným poradcom.

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Reviewed October 2026

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