> ## 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.

# Returning Customer Units Per Order: Repeat Buyer Basket Size

> Track average units per order for returning customers to measure repeat buyer basket size. Compare against new customers to identify loyalty-driven purchasing patterns.

<Tip>
  The average number of product units included in each returning customer's order.
</Tip>

## Formula

<Info>
  **Returning Customer Units Per Order** = [**Returning Customer Units Sold**](/reference/metrics/orders/counts/returning-customer-units-sold) ÷ **Returning Customer Orders**
</Info>

### Formula Components

| Metric                                                                                                  | Definition                                       |
| ------------------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| [**Returning Customer Units Sold**](/reference/metrics/orders/counts/returning-customer-units-sold)     | Total product units purchased by repeat buyers   |
| **Returning Customer Orders**                                                                           | Count of orders placed by returning customers    |
| [**customer\_type = returning\_customer**](/data-dictionary/measures-and-dimensions#visitor-dimensions) | Filter applied to both numerator and denominator |

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

***

## Example

Your store's returning customers averaged **3.1 units per order** in January:

| Segment             | Units/Order | Orders | Total Units |
| ------------------- | ----------- | ------ | ----------- |
| Returning Customers | 3.1         | 2,200  | 6,820       |
| New Customers       | 2.4         | 1,850  | 4,440       |
| All Customers       | 2.8         | 4,050  | 11,260      |

***

## How It Works

This metric divides total units purchased by returning customers by the number of repeat orders. Higher values than new customers suggest that loyal buyers are more comfortable adding multiple items to their cart, indicating trust and familiarity with your product catalog.

***

## When to Use

| Scenario                         | Action                                                            |
| -------------------------------- | ----------------------------------------------------------------- |
| Measuring loyalty impact         | Compare against new customers to quantify repeat buyer engagement |
| Evaluating retention programs    | Track if loyalty perks increase basket size over time             |
| Optimizing cross-sell strategies | Identify if returning customers respond to bundle offers          |
| Forecasting inventory            | Project unit demand from your retained customer base              |

***

## Related Metrics

| Metric                                                                                          | Relationship                                    |
| ----------------------------------------------------------------------------------------------- | ----------------------------------------------- |
| [Returning Customer Units Sold](/reference/metrics/orders/counts/returning-customer-units-sold) | Numerator: total units from returning customers |
| [Units Per Order](/reference/metrics/orders/counts/units-per-order)                             | Overall average across all customer types       |
| [New Customer Units Per Order](/reference/metrics/orders/counts/new-customer-units-per-order)   | Comparison metric for first-time buyers         |
| [Returning Customers](/reference/metrics/orders/customers/returning-customers)                  | Count of repeat buyers                          |

[See all Order Counts metrics →](/reference/metrics/orders/counts)