> ## 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: Trial Acquisition Cost

> Calculate cost per trial start to measure PLG efficiency. Track advertising spend required to acquire each free trial user.

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

## Formula

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

### Formula Components

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

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

***

## Example

Your SaaS company spent **\$36,000** on acquisition in June, generating **1,800 trial starts**.

| Channel             | Spend        | Trial Starts | Cost/Trial  |
| ------------------- | ------------ | ------------ | ----------- |
| Google Ads          | \$15,000     | 850          | \$17.65     |
| Meta                | \$12,000     | 600          | \$20.00     |
| LinkedIn            | \$6,000      | 250          | \$24.00     |
| Content Syndication | \$3,000      | 100          | \$30.00     |
| **Total**           | **\$36,000** | **1,800**    | **\$20.00** |

***

## How It Works

The metric divides total advertising spend by the number of trial start events tracked by the Upstack Pixel. This is a critical PLG metric because trial starts represent the beginning of the product experience and the primary opportunity for conversion.

***

## When to Use

| Scenario                      | Action                                           |
| ----------------------------- | ------------------------------------------------ |
| Set trial acquisition targets | Define acceptable cost per trial user            |
| Optimize channel mix          | Shift budget to lower-cost trial sources         |
| Calculate CAC                 | Multiply by inverse of trial conversion rate     |
| Benchmark performance         | Compare against industry trial acquisition costs |

***

## Related Metrics

| Metric                                                                                 | Relationship                        |
| -------------------------------------------------------------------------------------- | ----------------------------------- |
| [Trial Started](/reference/metrics/funnel/conversions/trial-started)                   | The denominator in this calculation |
| [Trial Started Value](/reference/metrics/funnel/conversions/trial-started-value)       | Revenue to compare against cost     |
| [Cost per Trial Converted](/reference/metrics/funnel/conversions/trial-converted-cost) | Full conversion cost metric         |

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