---
title: kurtosis() | Tiger Data Docs
description: Calculate the kurtosis from a one-dimensional statistical aggregate
---

Since [1.3.0](https://github.com/timescale/timescaledb-toolkit/releases/tag/1.3.0)

Calculate the kurtosis from the values in a statistical aggregate. The kurtosis is the fourth statistical moment. It is a measure of “tailedness” of a data distribution compared to a normal distribution.

## Samples

Calculate the kurtosis of a sample containing the integers from 0 to 100:

```
SELECT kurtosis(stats_agg(data))
  FROM generate_series(0, 100) data;
```

This returns something like:

```
kurtosis
----------
1.78195
```

## Arguments

The syntax is:

```
kurtosis(
  summary StatsSummary1D,
  [ method TEXT ]
) RETURNS DOUBLE PRECISION
```

| Name    | Type           | Default  | Required | Description                                                                                                                              |
| ------- | -------------- | -------- | -------- | ---------------------------------------------------------------------------------------------------------------------------------------- |
| summary | StatsSummary1D | -        | ✔        | The statistical aggregate produced by a `stats_agg` call                                                                                 |
| method  | TEXT           | `sample` | -        | The method used for calculating the kurtosis. The two options are `population` and `sample`, which can be abbreviated to `pop` or `samp` |

## Returns

| Column   | Type             | Description                                             |
| -------- | ---------------- | ------------------------------------------------------- |
| kurtosis | DOUBLE PRECISION | The kurtosis of the values in the statistical aggregate |