---
title: "How to Calculate the Total Purchase Value Using a Profile-Based Operation"
slug: "calculate-total-purchase-value"
updated: 2025-09-02T15:16:54Z
published: 2025-09-02T15:16:54Z
canonical: "docs.mapp.com/calculate-total-purchase-value"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mapp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How to Calculate the Total Purchase Value Using a Profile-Based Operation

## Goal

To calculate the total value of all purchases a contact makes in your shop.

## Background Information​

An operation is a type of profile-based automation. An operation consists of expression language applied to a profile attribute with the data type string, number or date. Use an operation to extract or modify data stored in an attribute.

## Procedure

1. In ​Automation​, create an event-based automation to store the value of the contact's last purchase in a custom user attribute ​**LastPurchaseValue**​.
2. In ​Administration​, create a new custom user attribute with the name ​TotalPurchaseValue​. The data type is ​**Number**​.
3. In ​Automation​, create a new**profile-based automation** with the type ​**Operation**​. The target attribute is ​TotalPurchaseValue​. The operation has the following expression:

```plaintext
${user.CustomAttribute['LastPurchaseValue']+ user.CustomAttribute['TotalPurchaseValue']}
```
4. Click the ​**Save**​ button.
5. Select the profile-based automation and click the ​**Activate**​ button. ⇒ The profile-based automation is now active.
6. Click the ​**Apply Automations​** button. ⇒ Engage applies the automation to all contacts in the system. This can take a long time. An email notifies you when the automation is finished.