Enter your two data sets in two separate columns
Click an empty cell where you want the result to appear
Use the formula `=CORREL(array1,array2)`
Select the first data range for `array1`
Select the second data range for `array2`
Press Enter
Use `=PEARSON(array1,array2)` as an alternative
Use the Data Analysis ToolPak if you want correlation for multiple variables
Go to the Data tab
Click Data Analysis
Choose Correlation
Select the input range
Check Labels in first row if applicable
Choose an output range
Click OK