Here you can get an Excel calculator of kurtosis, skewness, and other summary statistics.
Kurtosis Value Range
- Kurtosis can reach values from 1 to positive infinite.
- Normal distribution kurtosis = 3
- A distribution that is more peaked and has fatter tails than normal distribution has kurtosis value greater than 3 (the higher kurtosis, the more peaked and fatter tails). Such distribution is called leptokurtic or leptokurtotic.
- A distribution that is less peaked and has thinner tails than normal distribution has kurtosis value between 1 and 3. Such distribution is called platykurtic or platykurtotic.
The chart above shows a leptokurtic distribution. Kurtosis value is about 23 here. The grey line is normal distribution (kurtosis value = 3).
Excess Kurtosis Value Range
You can find in many sources that normal distribution kurtosis equals zero and kurtosis can be negative. These sources are not wrong, they are just discussing a different version of kurtosis – excess kurtosis, which is kurtosis relative to normal distribution and therefore equals kurtosis less 3.
As a result, the minimum possible value of excess kurtosis is minus 2, normal distribution excess kurtosis is zero, and positive excess kurtosis values indicate a distribution that is more peaked than normal distribution. Here you can see more details about the interpretation and calculation of excess kurtosis.
Calculating Kurtosis and Excess Kurtosis
Here you can see more details about kurtosis and excess kurtosis formulas for population and sample and how to calculate kurtosis in Excel.
Here you can get an Excel calculator of kurtosis, skewness, and other summary statistics.