Formula Guide

The Excel CORREL Function
explained simply

CORREL measures how strongly two sets of numbers move together. Near 1 means a strong positive relationship. Near -1 means an inverse relationship. Near 0 means no relationship.

ExcelPro · 6 min read · Updated June 2026

What does it do?

CORREL calculates the Pearson correlation coefficient between two sets of data — a number between -1 and 1 that measures the strength and direction of the linear relationship between them. It is widely used in data analysis, financial modelling, HR analytics, and scientific research.

Syntax

=CORREL(array1, array2)
ArgumentDescription
=CORREL(array1, array2)
array1 requiredThe first dataset — a range of numbers.
array2 requiredThe second dataset — must be the same size as array1.

Real examples

Example 1
Correlation between sales and spend
=CORREL(B2:B13, C2:C13)

Returns a value from -1 to 1.

Example 2
Correlation between temperature and energy use
=CORREL(A2:A365, B2:B365)
Example 3
Check if two metrics move together
=IF(CORREL(B2:B50,C2:C50)>0.7,"Strong positive","Weak or negative")

Flag strong correlations automatically.

Example 4
Multiple correlations in a table
=CORREL($B$2:$B$100, C$2:C$100)

Lock column B and copy right to build a correlation row.

Example 5
Correlation strength label
=CHOOSE(MATCH(ABS(CORREL(B2:B50,C2:C50)),{0,0.3,0.7,0.9},1),"Weak","Moderate","Strong","Very strong")

Returns a text label for the correlation strength.

FAQ

How do I interpret the result?
Values near 1: strong positive — both variables rise and fall together. Values near -1: strong negative — as one rises the other falls. Values near 0: little or no linear relationship.
Does correlation mean causation?
No. CORREL measures association only. A high correlation between two variables does not mean one causes the other — there may be a third variable driving both.
What size ranges work best?
At least 30 data points for meaningful correlation. With fewer points, correlation can be misleading due to random variation.

Understanding correlation coefficients

The CORREL result ranges from -1 to +1. A value of +1 means a perfect positive correlation — every time one variable increases, the other increases by a proportional amount. A value of -1 means a perfect negative correlation — as one rises, the other falls by a proportional amount. A value of 0 means no linear relationship exists between the two variables.

In practice, values are rarely exactly -1, 0, or +1. A general guide: 0 to 0.3 is a weak relationship, 0.3 to 0.7 is moderate, 0.7 to 1.0 is strong. These thresholds vary by field — a correlation of 0.4 might be considered strong in social science but weak in engineering.

Correlation only measures LINEAR relationships. Two variables can have a strong curved relationship and still produce a CORREL result near 0. Always plot your data in a scatter chart alongside the CORREL result to check whether the relationship actually looks linear.

⚠️ Correlation is not causation

CORREL tells you that two variables move together — it does not tell you why. Ice cream sales and drowning incidents are positively correlated (both increase in summer) but one does not cause the other. Always apply domain knowledge when interpreting correlation results.

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