---
title: "Scaling Tag Values"
canonical: "https://docs.rubiconwater.com/space/DC/2048721028/Scaling%20Tag%20Values"
format: markdown
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> Macro (toc)

Apply a linear scale to tag values to convert the raw measurements to a different unit before they are stored. The scaled value is calculated from the raw value as follows:

Tag Value = Tag Zero + Raw Value (Tag Span - Tag Zero)/Range

**Step 1**

Open the details form for the tag that you want to configure:

- In the Data Sources module, locate the site and tag and click  More Info to open the details form
- In the Site Tags module, use the  Find tool to locate and select the tag to view its details.

**Step 2**

Open the Scaling tab and specify the following details to establish two points where the Raw Value and the Tag Value are known.:

| **Property** | **Description** |
| --- | --- |
| Tag Zero | The Tag Value when the Raw Value is zero |
| Tag Span | The Tag Value when the Raw Value is the Tag Range |
| Tag Range | The Raw Value when the Tag Value is the Tag Span |

**Step 3**

Click **Save** to save your changes.

> ℹ️ **Examples**
> ℹ️ 
> ℹ️ Conversion: mm to m
> ℹ️ 
> ℹ️ - Tag Zero = 0
> ℹ️ - Tag Span = 1
> ℹ️ - Tag Range = 1000
> ℹ️ 
> ℹ️ Conversion: °C to °F
> ℹ️ 
> ℹ️ - Tag Zero = 32
> ℹ️ - Tag Span = 212
> ℹ️ - Tag Range = 100

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