Spearman's Correlation Calculator

Calculate Spearman's rank correlation coefficient to measure monotonic relationships between variables

Data Input

PairX ValueY ValueAction
1
2
3

Enter at least 3 data pairs to calculate Spearman's correlation. Maximum 30 pairs allowed.

Correlation Strength Guide

0.8 ≤ |ρ| ≤ 1.0Very Strong
0.6 ≤ |ρ| < 0.8Strong
0.4 ≤ |ρ| < 0.6Moderate
0.2 ≤ |ρ| < 0.4Weak
0.0 ≤ |ρ| < 0.2Very Weak

Formula Reference

General Formula

ρ = Cov(r(X), r(Y)) / (sd(r(X)) × sd(r(Y)))

When No Ties

ρ = 1 - (6∑d²) / (n(n²-1))

where d = rank difference

Quick Tips

Measures monotonic relationships, not just linear

Works with ordinal and continuous data

Less sensitive to outliers than Pearson

Values range from -1 to +1

Understanding Spearman's Rank Correlation

What is Spearman's Correlation?

Spearman's rank correlation coefficient (ρ) measures the strength and direction of monotonic relationships between two variables. Unlike Pearson's correlation, it works with ranked data and can detect non-linear monotonic patterns.

When to Use It?

  • Data doesn't meet normality assumptions
  • Ordinal or ranked data
  • Non-linear but monotonic relationships
  • Presence of outliers

Spearman vs Pearson

Spearman's Correlation

  • • Measures monotonic relationships
  • • Uses ranked values
  • • Works with ordinal data
  • • Less sensitive to outliers

Pearson's Correlation

  • • Measures linear relationships
  • • Uses raw values
  • • Requires continuous data
  • • More sensitive to outliers

Step-by-Step Calculation

1. Rank the Data

Assign ranks to each variable separately (lowest = rank 1)

2. Handle Ties

Assign average rank to tied values

3. Calculate Correlation

Apply Pearson's formula to the ranked data

4. Interpret Result

Assess strength and direction using standard guidelines