A/B Test Sample Size Calculator
Calculate the exact sample size needed for statistically valid A/B tests on your Facebook and Instagram ads.
Sample Per Variation
11,862
Total needed: 23,724
Estimated Duration
24 days
Long
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A/B test needs 11,862 visitors per variation (~24 days)
Calculated with the free Adship A/B Test Sample Size Calculator
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How to Use This Calculator
Enter Baseline
Your current conversion rate
Set MDE
Minimum improvement to detect
Choose Confidence
Significance and power levels
Get Results
Sample size and test duration
Typical Test Durations by Traffic
Based on 5% baseline, 20% MDE, 95% significance
Low Traffic
500/day
~48 days
Medium Traffic
2,000/day
~12 days
High Traffic
10,000/day
~3 days
Enterprise
50,000+/day
~1 days
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What Is A/B Test Sample Size?
A/B test sample size is the minimum number of visitors needed in each variation to detect a statistically significant difference. The required size depends on your baseline conversion rate, minimum detectable effect, significance level, and statistical power.
n = (Zα × √(2p̄(1-p̄)) + Zβ × √(p₁(1-p₁) + p₂(1-p₂)))² / (p₂ - p₁)²
Frequently Asked Questions
Frequently Asked Questions
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