> ## 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.

# Cohort Customers: Customer Count by Acquisition Period

> Track the number of customers acquired in each cohort period. Understand acquisition volume trends for your Shopify store's LTV analysis.

<Tip>
  The number of customers who made their first purchase in the cohort period.
</Tip>

## Formula

<Info>
  **Cohort Customers** = **COUNT** ( Unique Customers ) **WHERE** First Purchase in Cohort Period
</Info>

### Formula Components

| Metric                                                                       | Definition                                                 |
| ---------------------------------------------------------------------------- | ---------------------------------------------------------- |
| [**Unique Customers**](/reference/metrics/orders/customers/unique-customers) | Distinct customers with at least one order                 |
| **First Purchase**                                                           | Customer's initial order date determines cohort membership |

| Metadata        |                                     |
| --------------- | ----------------------------------- |
| **Type**        | Number                              |
| **Data Source** | [Shopify](/sources/catalog/shopify) |
| **Aggregation** | Count                               |

***

## Example

Monthly customer acquisition cohorts for Q1 2024:

| Cohort Period | Cohort Customers | Avg First Order Value |
| ------------- | ---------------- | --------------------- |
| January 2024  | 1,250            | \$85                  |
| February 2024 | 980              | \$92                  |
| March 2024    | 1,420            | \$78                  |

***

## How It Works

Cohort Customers counts the distinct customers who made their first-ever purchase during a specific period. This forms the denominator for all per-customer cohort metrics like LTV and cohort revenue. Each customer belongs to exactly one cohort based on their initial purchase date from your Shopify store.

***

## When to Use

| Scenario                    | Action                                                |
| --------------------------- | ----------------------------------------------------- |
| Normalizing cohort metrics  | Divide revenue by cohort size for per-customer values |
| Tracking acquisition growth | Monitor how customer acquisition scales over time     |
| Evaluating campaign reach   | See how many new customers each campaign acquired     |
| Comparing cohort quality    | Larger cohorts aren't always better—pair with LTV     |

***

## Related Metrics

| Metric                                                                       | Relationship                         |
| ---------------------------------------------------------------------------- | ------------------------------------ |
| [New Customers](/reference/metrics/orders/customers/new-customers)           | Non-cohort new customer count        |
| [Cohort Retention %](/reference/metrics/orders/ltv/cohort-retention-percent) | How many repurchase over time        |
| [Cohort Gross Revenue](/reference/metrics/orders/ltv/cohort-gross-revenue)   | Total revenue from the cohort        |
| [CAC](/reference/metrics/orders/performance/cac)                             | Cost to acquire each cohort customer |

[See all LTV metrics →](/reference/metrics/orders/ltv)