CORREL(array1,array2)
CORREL returns the correlation coefficient of two data sets.
Let us assume that the cells A1, A2, ..., A5 contain numbers 11.4, 17.3, 21.3, 25.9, and 40.1, and the cells B1, B2, ... B5 23.2, 25.8, 29.9, 33.5, and 42.7. Then
CORREL(A1:A5,B1:B5) equals 0.996124788.