KURT(n1, n2, ...)
KURT returns an unbiased estimate of the kurtosis of a data set.
Note, that this is only meaningful if the underlying distribution really has a fourth moment. The kurtosis is offset by three such that a normal distribution will have zero kurtosis.
Let us assume that the cells A1, A2, ..., A5 contain numbers 11.4, 17.3, 21.3, 25.9, and 40.1. Then
KURT(A1:A5) equals 1.234546305.