> ## 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.

# Cost per Trial Started: Track Trial Acquisition Cost

> Track the average ad spend per trial start. Calculate your cost to acquire trial users.

<Tip>
  Cost per Trial Started measures the average advertising spend required to generate one free trial start.
</Tip>

## Formula

<Info>
  **Cost per Trial Started** = **Channel Spend** ÷ **Trial Started Events**
</Info>

### Formula Components

| Metric                                                                   | Definition                              |
| ------------------------------------------------------------------------ | --------------------------------------- |
| **Channel Spend**                                                        | Total advertising spend across channels |
| [**Trial Started**](/reference/metrics/funnel/conversions/trial-started) | Total trial start events                |

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

***

## Example

Your SaaS spent **\$20,000** on ads and generated **500 trial starts** this month.

| Channel    | Spend        | Trials Started | Cost per Trial |
| ---------- | ------------ | -------------- | -------------- |
| Google Ads | \$10,000     | 220            | \$45.45        |
| Facebook   | \$6,000      | 180            | \$33.33        |
| LinkedIn   | \$4,000      | 100            | \$40.00        |
| **Total**  | **\$20,000** | **500**        | **\$40.00**    |

***

## How It Works

This metric divides your total channel spend by the number of trial starts. For product-led growth companies, this is a key efficiency metric that feeds into your overall customer acquisition cost when combined with trial-to-paid conversion rates.

***

## When to Use

| Scenario             | Action                                          |
| -------------------- | ----------------------------------------------- |
| CAC calculation      | Calculate full acquisition cost with conversion |
| Channel optimization | Find most efficient trial sources               |
| PLG efficiency       | Measure product-led acquisition cost            |
| Budget planning      | Project spend for trial targets                 |

***

## Related Metrics

| Metric                                                                                 | Relationship          |
| -------------------------------------------------------------------------------------- | --------------------- |
| [Trial Started](/reference/metrics/funnel/conversions/trial-started)                   | Count of trial starts |
| [Trial Started Value](/reference/metrics/funnel/conversions/trial-started-value)       | Value of trial starts |
| [Cost per Trial Converted](/reference/metrics/funnel/conversions/trial-converted-cost) | Full conversion cost  |

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