# EXPAND
URL: https://docs.valsight.ai/expand/
Description: The EXPAND function creates a full cross product of existing rows with all values of specified levels, used to initialize empty data rooms or add dimensions to nodes.
**Category:** [Dimensionality & hierarchies](/dimensionality-hierarchies/)

## Overview

The **EXPAND** function **expands a node** by creating a full cross product of all existing rows **with all values** **of the specified level(s).**

Use this function when you need to create an empty data room (a set of rows with placeholder values) that can serve as a driver inside [ROLLFORWARD\_ADVANCED](/rollforward-advanced/), or when you want to expand an existing node with additional levels.

## Syntax

`EXPAND('Node', "Level1" [, "Level2", ...])`

**Example usage:** `EXPAND('Growth Rate', "Product")`

## Parameters

| Parameter               | Description                                                                                             | Type                     | Required |
| ----------------------- | ------------------------------------------------------------------------------------------------------- | ------------------------ | -------- |
| **Node**                | Input node or scalar value, specified in single quotes (e.g. `'Growth Rate'`) or as a number (e.g. `0`) | Node reference or number | Yes      |
| **Level1, Level2, ...** | Level names to expand, specified in double quotes (e.g. `"Product"`)                                    | Level name               | Yes      |

## Output shape

| Aspect         | Behavior                                                                                                              |
| -------------- | --------------------------------------------------------------------------------------------------------------------- |
| Dimensionality | Adds the specified levels (and their upper levels in the dimension hierarchy) to the result                           |
| Values         | Existing values are duplicated across all members of the new level(s). Scalar inputs fill every cell with that value. |
| Row count      | Full cross product                                                                                                    |

## Watch out

* EXPAND creates the **full cross product of all values in the specified level(s)**. If you only need specific values, use EXPANDSINGLE instead.
* Expanding a node copies each row's value into every member of the new level. Be aware this **changes totals**. For example, if a row has value 100 and you expand across 3 products, the sum becomes 300 instead of 100.

## Examples

### Expand a scalar to full dimensionality

Initialize an empty simulation node with zeros across all years, regions, and products.

**Formula:** `EXPAND(0, "Year", "Region", "Product")`

| Year | Region | Product | EXPAND Result |
| ---- | ------ | ------- | ------------- |
| 2025 | EMEA   | Alpha   | 0             |
| 2025 | EMEA   | Beta    | 0             |
| 2025 | APAC   | Alpha   | 0             |
| 2025 | APAC   | Beta    | 0             |
| 2026 | EMEA   | Alpha   | 0             |
| ...  | ...    | ...     | ...           |

The scalar `0` is replicated across every combination of Year × Region × Product.
The result makes the simulation node eligible for use with ROLLFORWARD.

### Expand a node to add a dimension

A growth-rate node only has a Year level, but should also include the Product level.

**Input node:** `'Growth Rate'`

| Year | Value |
| ---- | ----- |
| 2025 | 0.03  |
| 2026 | 0.05  |

**Formula:** `EXPAND('Growth Rate', "Product")`

| Year | Product | EXPAND Result |
| ---- | ------- | ------------- |
| 2025 | Alpha   | 0.03          |
| 2025 | Beta    | 0.03          |
| 2026 | Alpha   | 0.05          |
| 2026 | Beta    | 0.05          |

The same growth rate per year is now available for each product.

### Expand into a finer level within an existing dimension

A revenue node already has a `"Region"` level. You want to break it down to individual countries, a finer level in the same dimension hierarchy.

**Input node:** `'Revenue Target'`

| Year      | Region | Value   |
| --------- | ------ | ------- |
| 2025      | EMEA   | 500     |
| 2025      | APAC   | 300     |
| **Total** |        | **800** |

**Formula:** `EXPAND('Revenue Target', "Country")`

| Year      | Region | Country   | EXPAND Result |
| --------- | ------ | --------- | ------------- |
| 2025      | EMEA   | Germany   | 500           |
| 2025      | EMEA   | France    | 500           |
| 2025      | APAC   | Japan     | 300           |
| 2025      | APAC   | Australia | 300           |
| **Total** |        |           | **1600**      |

Because `"Country"` is a finer level below `"Region"` in the hierarchy, EXPAND adds only the child values belonging to each region, not a full cross product of all countries with all regions.

Note that the values are duplicated into each child row, so totals will increase.

## Related

| Function                                        | When to use instead                                                       |
| ----------------------------------------------- | ------------------------------------------------------------------------- |
| [EXPANDSINGLE](/expandsingle/)                  | When you only need specific level values instead of a full cross product. |
| [DROPLEVEL](/droplevel/)                        | When you need to remove levels instead of adding them.                    |
| [ROLLUP](/rollup/)                              | When you want to aggregate to fewer levels.                               |
| [ROLLFORWARD\_ADVANCED](/rollforward-advanced/) | When you need to project expanded driver nodes forward in time.           |