> ## Documentation Index
> Fetch the complete documentation index at: https://cubed3-feat-druid-driver-streaming.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Calculated fields

> Create ad-hoc custom dimensions and measures with Semantic SQL in workbooks, with help from AI or the field picker.

Calculated fields are ad-hoc dimensions and measures you add only to the current
workbook report. They do not change the shared data model.

As described in [Semantic SQL](/docs/introduction#semantic-sql), Cube routes
analysis through the semantic layer instead of sending arbitrary SQL straight to
the warehouse. The runtime validates every request and applies your security
policies. Semantic SQL builds on Postgres-compatible SQL—including the
`MEASURE()` function—so you can express derived logic on top of existing
semantic definitions with both flexibility and governance.

Calculated fields are expressed as Semantic SQL and pushed down to the Cube
backend for evaluation. The semantic layer compiles them with the rest of the
query—rather than applying them only in the browser—so the same validation,
governance, and warehouse execution path apply as for any other Semantic SQL
analysis.

## Using AI to create calculated fields

You can ask the Cube AI agent to create custom calculations in natural language.
The agent can add or refine calculated fields from different parts of the
product—for example while exploring in **Analytics chat** or working in
**Workbooks**—so you are not limited to a single entry point when you want a new
metric or dimension for the analysis in front of you.

## Creating calculated fields in UI

You can also build and edit calculated fields directly in the workbook. New
fields appear in the **Calculated fields** section of the field picker sidebar.

### Aggregations from existing dimensions

Right-click a dimension column header and choose an aggregation to create a
calculated field automatically. Available aggregations depend on the column type:

| Column type     | Available aggregations                 |
| --------------- | -------------------------------------- |
| Number          | Count Distinct, Sum, Average, Min, Max |
| Time            | Count Distinct, Min, Max               |
| String, Boolean | Count Distinct                         |

### Calculations from existing measures

Open the menu on a measure column header and use the **Calculations** submenu
for derived calculations:

| Calculation            | Description                                             |
| ---------------------- | ------------------------------------------------------- |
| % of total             | Ratio of the measure value to the total across all rows |
| % of previous          | Ratio of the measure value to the previous row's value  |
| % change from previous | Percentage change compared to the previous row          |
| Running total          | Cumulative sum of the measure across rows               |

<Info>
  **% of previous**, **% change from previous**, and **Running total** require at
  least one dimension in the query.
</Info>

Which calculations are offered depends on the measure’s aggregation type:

| Aggregation type        | Available calculations |
| ----------------------- | ---------------------- |
| Count, Sum              | All calculations       |
| Min, Max                | Running total          |
| Average, Count Distinct | None                   |

### Filtered measures

When working with query **Results**, pivot so at least one dimension is on
columns, then open the header menu on a **pivoted measure column** and choose
**Create filtered measure**. Cube adds a calculated measure that applies the
column’s slice—for example, from **Count** broken down by **Status**, you get a
measure that only aggregates rows matching that status (such as completed
orders only).

The option appears only for **native** measures on pivoted columns, not for
calculated fields. The same flow works in **Explore** when results are pivoted
the same way.

### Editing a calculated field

Select a calculated field in the sidebar to open the editor. You can change its
**name** and **SQL expression**, then choose **Update** to apply.