How does this differ from regression?
Correlation measures strength of association only. If you also need slope and predictions, jump to the linear regression calculator.
Step-by-step walkthrough
Correlation Coefficient Calculator Guide
Use this companion guide beside the interactive calculator to make sure you understand the “why” behind every click. Each section includes the classroom explanation, student-friendly language, and quick practice prompts.
Before you start
Collect the data points listed below and double-check their units. Keeping an organized “givens” list is one of the fastest ways to reduce math errors and impress exam graders.
- correlation
- pearson r
- covariance
Detailed procedure
Step 1
Paste X values and Y values in the same order.
Step 2
Ensure each list has at least two numeric entries.
Step 3
Review r, R², covariance, and each sample standard deviation.
Teaching & troubleshooting tips
Why does r sometimes report 0?
If one list has no variation (all values identical) the standard deviation is zero, so Pearson r cannot be computed and the calculator reports 0 as a neutral result.