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

# Signup Completed Cost: Ad Spend per Registration

> Calculate advertising cost per completed registration. Measure signup acquisition cost.

<Tip>
  Signup Completed Cost measures how much you spend on advertising for each completed registration.
</Tip>

## Formula

<Info>
  **Signup Completed Cost** = **Ad Spend** ÷ **Signup Completed**
</Info>

### Formula Components

| Metric                                                                         | Definition                                         |
| ------------------------------------------------------------------------------ | -------------------------------------------------- |
| [**Ad Spend**](/reference/metrics/advertising/blended/blended-spend)           | Total advertising cost from connected ad platforms |
| [**Signup Completed**](/reference/metrics/funnel/conversions/signup-completed) | Count of completed registrations                   |

| Metadata        |                         |
| --------------- | ----------------------- |
| **Type**        | Currency                |
| **Data Source** | [Upstack Pixel](/pixel) |
| **Aggregation** | Ratio                   |

***

## Example

You spent **\$5,000** on Meta ads in January and drove **500 completed signups**.

| Metric                | Value   | Notes                    |
| --------------------- | ------- | ------------------------ |
| Ad Spend              | \$5,000 | Monthly advertising cost |
| Signup Completed      | 500     | Completed registrations  |
| Signup Completed Cost | \$10.00 | Cost per signup          |

***

## How It Works

This metric divides your total ad spend by the number of completed signups. It represents your cost per registered user, a key input for calculating customer acquisition cost.

***

## When to Use

| Scenario            | Action                                    |
| ------------------- | ----------------------------------------- |
| Registration CPA    | Track cost per completed signup           |
| Channel comparison  | Compare registration costs across sources |
| Budget optimization | Allocate spend to efficient channels      |
| CAC calculation     | Factor into total acquisition cost        |

***

## Related Metrics

| Metric                                                                                 | Relationship                        |
| -------------------------------------------------------------------------------------- | ----------------------------------- |
| [Signup Completed](/reference/metrics/funnel/conversions/signup-completed)             | The denominator in this calculation |
| [Signup Completed Value](/reference/metrics/funnel/conversions/signup-completed-value) | Value from completions              |
| [Account Created Cost](/reference/metrics/funnel/conversions/account-created-cost)     | Cost per account creation           |

[See all Conversions metrics →](/reference/metrics/funnel/conversions)