---
title: ES|QL EVAL command
description: 
url: https://www.elastic.co/elastic/docs-builder/docs/3028/reference/query-languages/esql/commands/eval
products:
  - Elasticsearch
---

# ES|QL EVAL command
<applies-to>
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
</applies-to>

The `EVAL` processing command enables you to append new columns with calculated
values.

## Syntax

```esql
EVAL [column1 =] value1[, ..., [columnN =] valueN]
```


## Parameters

<definitions>
  <definition term="columnX">
    The column name.
    If a column with the same name already exists, the existing column is dropped.
    If a column name is used more than once, only the rightmost duplicate creates a column.
  </definition>
  <definition term="valueX">
    The value for the column. Can be a literal, an expression, or a
    [function](/elastic/docs-builder/docs/3028/reference/query-languages/esql/esql-functions-operators#esql-functions).
    Can use columns defined left of this one.
  </definition>
</definitions>


## Description

The `EVAL` processing command enables you to append new columns with calculated
values. `EVAL` supports various functions for calculating values. Refer to
[Functions](/elastic/docs-builder/docs/3028/reference/query-languages/esql/esql-functions-operators#esql-functions) for more information.

## Examples

The following examples show common `EVAL` patterns.

### Append a calculated column

```esql
FROM employees
| SORT emp_no
| KEEP first_name, last_name, height
| EVAL height_feet = height * 3.281, height_cm = height * 100
```


| first_name:keyword | last_name:keyword | height:double | height_feet:double | height_cm:double   |
|--------------------|-------------------|---------------|--------------------|--------------------|
| Georgi             | Facello           | 2.03          | 6.66043            | 202.99999999999997 |
| Bezalel            | Simmel            | 2.08          | 6.82448            | 208.0              |
| Parto              | Bamford           | 1.83          | 6.004230000000001  | 183.0              |


### Overwrite an existing column

If the specified column already exists, the existing column will be dropped, and
the new column will be appended to the table:
```esql
FROM employees
| SORT emp_no
| KEEP first_name, last_name, height
| EVAL height = height * 3.281
```


| first_name:keyword | last_name:keyword | height:double     |
|--------------------|-------------------|-------------------|
| Georgi             | Facello           | 6.66043           |
| Bezalel            | Simmel            | 6.82448           |
| Parto              | Bamford           | 6.004230000000001 |


### Use an expression as the column name

Specifying the output column name is optional. If not specified, the new column
name is equal to the expression. The following query adds a column named
`height*3.281`:
```esql
FROM employees
| SORT emp_no
| KEEP first_name, last_name, height
| EVAL height * 3.281
```


| first_name:keyword | last_name:keyword | height:double | height * 3.281:double |
|--------------------|-------------------|---------------|-----------------------|
| Georgi             | Facello           | 2.03          | 6.66043               |
| Bezalel            | Simmel            | 2.08          | 6.82448               |
| Parto              | Bamford           | 1.83          | 6.004230000000001     |


### Reference an auto-named column in a subsequent command

Because this name contains special characters,
[it needs to be quoted](/elastic/docs-builder/docs/3028/reference/query-languages/esql/esql-syntax#esql-identifiers)
with backticks (```) when using it in subsequent commands:
```esql
FROM employees
| EVAL height * 3.281
| STATS avg_height_feet = AVG(`height * 3.281`)
```


| avg_height_feet:double |
|------------------------|
| 5.801464200000001      |