Statistical Significance
Made Simple

The layman-friendly A/B testing calculator. Start with your metric, not the math.

Which Statistical Test Do You Need?

Select your metric type to find the perfect statistical method.

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Yes/No - Binary

Tests binary participation results.

  • Conversion rate
  • Click-through rate (CTR)
  • Signup rate
Use: Z-Test Available in Extension
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Counts (Skewed)

For count data with power users (aggregate totals).

  • Reviews per product
  • Social shares per post
  • Items per shopping cart
Use: Quasi-Poisson Test Available in Extension
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Counts (Even)

Tests differences in event frequencies with predictable patterns.

  • Customer calls per hour
  • Server errors per day
  • Newsletter signups per day
Use: Poisson Test Available in Extension
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Average (Skewed)

For continuous average metrics with outliers.

  • Average order value
  • Average session duration
  • Average lifetime value
Recommended: Welch's T-Test Not in Extension - Search Online
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Average (Normal)

For continuous average metrics with consistent values.

  • Average response time
  • Average satisfaction rating
  • Average app load time
Recommended: Student's T-Test Not in Extension - Search Online
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Ranked/Ordinal

For non-normal continuous metrics or ordinal rankings.

  • Satisfaction ratings (1-5)
  • Net Promoter Score
  • Loading speed (outliers)
Recommended: Mann-Whitney U Test Not in Extension - Search Online
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Categorical (3+)

For comparing distributions across multiple categories.

  • Product category selection
  • Payment method choice
  • User segment distribution
Recommended: Chi-Square Test Not in Extension - Search Online
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Assumption-Free

For any metric without distributional assumptions.

  • Complex business metrics
  • Median metrics
  • Percentile metrics
Recommended: Bootstrap/Permutation Not in Extension - Search Online

Percentage Calculator

Quickly calculate percentages, increases, and decreases.

  • % change between values
  • What is X% of Y?
  • X is what % of Y?
Recommended: Percentage Calculator Available in Extension

Powerful Features

Instant Calculations

Get p-values, confidence intervals, and lift estimates instantly as you type.

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Smart Detection

Capture numbers directly from your webpage using an OCR screenshotter to save time copy-pasting.

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Side Panel Access

Always available in your browser side panel without blocking your view.

See It In Action

Explore the intuitive interface designed for quick statistical analysis

Z-Test Calculator

Z-Test Calculator

Calculate statistical significance for binary metrics like conversion rates

Metric Selection Helper

Smart Metric Guidance

Interactive wizard helps you choose the right statistical test for your data

Percentage Calculator

Percentage Calculator

Quick percentage calculations without leaving your workflow