---
title: "Create and manage derived fields | Lansweeper Platform"
slug: "create-and-manage-derived-fields"
description: "Add and manage derived fields in Lansweeper to create computed columns on your asset dataset using the expression language, currently in feature preview."
updated: 2026-07-03T13:23:23Z
published: 2026-07-03T13:23:23Z
canonical: "docs.lansweeper.com/create-and-manage-derived-fields"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lansweeper.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create and manage derived fields

Derived fields let you add computed columns to your asset dataset. For more information, see [About derived fields](/docs/about-derived-fields).

## Prerequisites

- **View** permission (required for all derived field actions)
- **Create** permission to add new derived fields
- **Edit** permission to modify existing derived fields
- **Delete** permission to remove derived fields

Contact your Lansweeper administrator if you don't have the necessary permissions.

## Create a derived field

1. Go to **Assets > Fields > Derived fields**.
2. Select **Create derived field**.
3. Enter a name in the **Name** field.
4. Optionally, enter a **Description** to explain what the field calculates and when to use it.
5. Write your expression in the expression editor. See [Use the expression editor](/docs/create-and-manage-derived-fields#use-the-expression-editor) for guidance on the editor's features.
6. Select **Save**.

The derived field is now part of the asset dataset and can be added to dashboards like any other field.

## Use the expression editor

The expression editor gives you a structured environment for writing and testing derived field expressions.

### Browse functions and fields

The left panel has two tabs:

- **Functions** — Browse available functions grouped by category. Drag and drop or type the function to add it to the expression. Hover over a function name to see its description and type signature.
- **Fields** — Browse the asset dataset fields you can reference in your expression. Drag and drop or type the field to add it to the expression.

### Write an expression

Enter your expression in the editor area on the right. As you type:

- **Syntax highlighting** distinguishes field references, function names, operators, and literals.
- **Autocomplete** suggests completions as you type. Select a suggestion to insert it.
- **Inline validation** flags errors with a red underline.

Field references use square brackets around the field name: `[assetName]`, `[diskDrives.size]`. If a field name contains spaces, use its exact display name: `[Last successful scan]`, `[Warranty end date]`.

For a full syntax reference, see [Derived fields expression language reference](/docs/derived-fields-expression-language-reference).

### Preview your expression

A preview of your expression shows the calculated value for each sample row, so you can confirm the output before saving.

If the expression contains errors, the preview won't run. Fix the flagged issues in the editor.

## Add a derived field to a dashboard

After you save a derived field, it becomes part of the asset dataset. You add it to a dashboard the same way you add any other asset field.

1. Go to **Dashboard**.
2. Select **Create dashboard**, or select the dashboard you want to edit and select **More actions > Edit**.
3. Add the derived field to the dashboard.

Lansweeper evaluates the expression for each row every time the dashboard loads. Custom fields are available the same way.

## Edit a derived field

1. Go to **Assets > Fields > Derived fields**.
2. Find the derived field you want to update.
3. Select **... > Edit**.
4. Make your changes in the **Edit derived field** dialog.
5. Select **Save**.

              Changes apply everywhere the field is used

              

Updating a derived field's expression affects every dashboard that includes it. The updated calculation takes effect immediately after saving.

## Delete a derived field

1. Go to **Assets > Fields > Derived fields**.
2. Find the derived field you want to update.
3. Select **... > Delete**.
4. Select **Delete** to confirm the deletion.

              Deletion can't be undone

              

Deleting a derived field removes it from every dashboard that uses it. Verify the field isn't in active use before deleting it.

## Next steps

- [Derived fields expression language reference](/docs/derived-fields-expression-language-reference)
- [Derived fields function reference](/docs/derived-fields-function-reference)