> ## 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.

# New Customer Units Per Order: First-Purchase Basket Size

> Track average units per order for new customers to understand first-purchase basket behavior. Compare against returning customers to optimize acquisition.

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

## Formula

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

### Formula Components

| Metric                                                                                            | Definition                                         |
| ------------------------------------------------------------------------------------------------- | -------------------------------------------------- |
| [**New Customer Units Sold**](/reference/metrics/orders/counts/new-customer-units-sold)           | Total product units purchased by first-time buyers |
| **New Customer Orders**                                                                           | Count of orders placed by first-time customers     |
| [**customer\_type = new\_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 new customers averaged **2.4 units per order** in January:

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

***

## How It Works

This metric divides total units purchased by new customers by the number of first-time orders. It measures initial basket size behavior, helping you understand whether new customers buy single items or multiple products on their first visit.

***

## When to Use

| Scenario                       | Action                                                |
| ------------------------------ | ----------------------------------------------------- |
| Analyzing acquisition quality  | Compare new vs. returning to spot basket size gaps    |
| Optimizing product bundles     | Track if bundle promotions increase first-order units |
| Evaluating channel performance | Identify which channels bring customers who buy more  |
| Forecasting inventory          | Project unit demand from new customer acquisition     |

***

## Related Metrics

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

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