> ## 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.

# Blended CPA: Cost Per Acquisition Across All Channels

> Track your blended CPA to understand acquisition costs across Meta, Google, and TikTok combined. Optimize your overall marketing efficiency.

<Tip>
  Blended CPA measures the average cost to acquire each purchase conversion across all your advertising channels combined.
</Tip>

## Formula

<Info>
  **Blended CPA** = **Blended Spend** ÷ **Blended Purchases**
</Info>

### Formula Components

| Metric                                                                                                | Definition                                                |
| ----------------------------------------------------------------------------------------------------- | --------------------------------------------------------- |
| [**Blended Spend**](/reference/metrics/advertising/blended/blended-spend/blended-spend)               | Total advertising spend across all connected platforms    |
| [**Blended Purchases**](/reference/metrics/advertising/blended/blended-conversions/blended-purchases) | Total attributed purchase conversions across all channels |

| Metadata        |                                                                                                     |
| --------------- | --------------------------------------------------------------------------------------------------- |
| **Type**        | Currency                                                                                            |
| **Data Source** | [Meta Ads](/sources/facebook-ads), [Google Ads](/sources/google-ads), [TikTok Ads](/sources/tiktok) |
| **Aggregation** | Ratio                                                                                               |

***

## Example

Your store spent **\$12,500** across all advertising channels in March and generated **250 attributed purchases**.

| Channel     | Spend        | Purchases | Channel CPA |
| ----------- | ------------ | --------- | ----------- |
| Meta        | \$6,000      | 150       | \$40.00     |
| Google      | \$4,000      | 70        | \$57.14     |
| TikTok      | \$2,500      | 30        | \$83.33     |
| **Blended** | **\$12,500** | **250**   | **\$50.00** |

***

## How It Works

Blended CPA aggregates total spend and total attributed purchases from all connected ad platforms, then calculates the average cost per conversion. This gives you a single efficiency metric across your entire paid media mix rather than evaluating each channel separately.

***

## When to Use

| Scenario                            | Action                                                      |
| ----------------------------------- | ----------------------------------------------------------- |
| Setting overall acquisition targets | Compare blended CPA to customer lifetime value              |
| Budget allocation decisions         | Identify if total spend is generating efficient conversions |
| Monthly performance reviews         | Track acquisition cost trends across all channels           |
| Scaling paid media                  | Monitor if efficiency holds as you increase total spend     |

***

## Related Metrics

| Metric                                                                                            | Relationship                                       |
| ------------------------------------------------------------------------------------------------- | -------------------------------------------------- |
| [Blended Spend](/reference/metrics/advertising/blended/blended-spend/blended-spend)               | Numerator — total ad spend across platforms        |
| [Blended Purchases](/reference/metrics/advertising/blended/blended-conversions/blended-purchases) | Denominator — total attributed purchases           |
| [Blended ROAS](/reference/metrics/advertising/blended/blended-efficiency/blended-roas)            | Inverse efficiency metric measuring revenue return |

[See all Blended Efficiency metrics →](/reference/metrics/advertising/blended/blended-efficiency)