> ## 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.

# Payment Failed Cost: Ad Spend Associated with Failed Payments

> Calculate advertising cost associated with failed payments. Measure wasted acquisition cost.

<Tip>
  Payment Failed Cost measures advertising spend associated with customers whose payments failed.
</Tip>

## Formula

<Info>
  **Payment Failed Cost** = **Ad Spend** ÷ **Payment Failed**
</Info>

### Formula Components

| Metric                                                                     | Definition                                         |
| -------------------------------------------------------------------------- | -------------------------------------------------- |
| [**Ad Spend**](/reference/metrics/advertising/blended/blended-spend)       | Total advertising cost from connected ad platforms |
| [**Payment Failed**](/reference/metrics/funnel/conversions/payment-failed) | Count of failed payments                           |

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

***

## Example

You spent **\$10,000** on advertising in January and had **89 failed payments**.

| Metric              | Value    | Notes                    |
| ------------------- | -------- | ------------------------ |
| Ad Spend            | \$10,000 | Monthly advertising cost |
| Payment Failed      | 89       | Failed payments          |
| Payment Failed Cost | \$112.36 | Ad spend per failure     |

***

## How It Works

This metric divides your total ad spend by the number of failed payments. It helps contextualize acquisition cost against payment success, identifying potential issues with customer quality or payment methods.

***

## When to Use

| Scenario                | Action                                      |
| ----------------------- | ------------------------------------------- |
| Acquisition quality     | Identify sources with high payment failures |
| Channel optimization    | Reduce spend on high-failure sources        |
| Payment method analysis | Compare failure rates by payment type       |
| Recovery prioritization | Focus on high-value failed payments         |

***

## Related Metrics

| Metric                                                                                 | Relationship                        |
| -------------------------------------------------------------------------------------- | ----------------------------------- |
| [Payment Failed](/reference/metrics/funnel/conversions/payment-failed)                 | The denominator in this calculation |
| [Payment Failed Value](/reference/metrics/funnel/conversions/payment-failed-value)     | Revenue at risk                     |
| [Payment Succeeded Cost](/reference/metrics/funnel/conversions/payment-succeeded-cost) | Cost for successful payments        |

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