> For the complete documentation index, see [llms.txt](https://help.taglo.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.taglo.io/units/defining-a-unit.md).

# Defining a Unit

<figure><img src="/files/S9TIXw5wSG7ny2z9OGPT" alt="Screenshot of the Unit step of the Variable dialog"><figcaption><p>Unit step of the Variable wizard</p></figcaption></figure>

{% hint style="info" %}
If this is your first time defining a Unit, we recommend reading the [**Introduction to Units**](/units/introduction-to-units.md) first
{% endhint %}

You will most commonly define [**Units**](/units/introduction-to-units.md) as part of the [**Variable wizard**](/variables/variable-basics/unit-and-calculations.md). You will only need to define a Unit if your Variable is an `Assumptions` Variable, or if you select the `Specify Unit` option for a `Calculation` Variable.

The Unit step is simply a list of [**Unit Parts**](/units/key-unit-concepts.md#compound-units), in a standard [**List View**](/using-taglo-software/the-taglo-interface/list-views.md), in which you can *Add*, *Edit* and *Duplicate* Unit Parts. The resulting Unit is shown as a formula at the top of the step.

Each Unit Part can be edited in a separate wizard, or specific properties can be edited individually by clicking on one of the shortcut buttons displayed.

<details>

<summary>Shortcut buttons (as per above image)</summary>

* <img src="/files/x4kPlDgJdDgK1HpNg1Sk" alt="" data-size="line">Change the base [**Tag**](/tags/introduction-to-tags.md) and/or [**Unit Factor**](/units/advanced-units.md#factors)
* <img src="/files/Gf4j7du2pSaDxLOmKEO1" alt="" data-size="line">Change the Order
* <img src="/files/1uEnXhkBZA4dzfbzL0oC" alt="" data-size="line">Change the Time Type (`Flow`, `Balance`, `Flow (Constant)`, `Balance (Constant)`
* <img src="/files/a12xKtWy17QWPTefdH03" alt="" data-size="line">`Change the Time Offset`
* <img src="/files/X9LobYArzEhJN7lJLX5E" alt="" data-size="line">`Add a Context modifier`
* <img src="/files/jp5CMy5KwYV6YGAQqC5w" alt="" data-size="line">Multiply the Order by -1
* <img src="/files/S7OEQa28VuuRd3eoxVTy" alt="" data-size="line">Make a copy of the Unit Part

</details>

{% hint style="info" %}
Functionality of the Unit step depends on the context. You will find additional options if your Variable has [**Dimensions**](/dimensions/introduction-to-dimensions.md), or if you are creating a [**Data Point**](/assumptions/assumptions-wizard/linking-to-external-data.md) from scratch.

These differences are covered in the relevant sections of documentation.
{% endhint %}

## Default Unit

You can set a default Unit for new Variables by navigating to [**Model Settings**](/models/model-editor.md#model-settings)**.**