Correlation calculator

Pearson correlation measures the linear association between matching numeric observations.

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First paired series

Second paired series

Answer

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Pearson correlation measures the linear association between matching numeric observations.

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Precision and calculation record

Decimal places in numeric results and text downloads

Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.

Saved scenario

Save the current answer, then change an input to compare. This clears when you leave.

Formula and assumptions

Both series need at least two points and nonzero variation. Correlation does not establish causation, and outliers or nonlinear relationships can make it misleading.

In a list, use spaces, new lines, semicolons, or commas followed by a space. A comma between groups of three digits is a thousands separator.

Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.

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Updated 2026-09-26

Using Correlation calculator

Pearson correlation measures the linear association between matching numeric observations.

Both series need at least two points and nonzero variation. Correlation does not establish causation, and outliers or nonlinear relationships can make it misleading.

Next: Basic calculator

A worked example

With first paired series = 1 2 3, second paired series = 2 4 6, the pearson correlation r is 1.

Before you use the result

Both series need at least two points and nonzero variation. Correlation does not establish causation, and outliers or nonlinear relationships can make it misleading.

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ToolOctopus. “Correlation calculator.” Updated 2026-09-26. https://tooloctopus.com/correlation-calculator.

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