> ## Documentation Index > Fetch the complete documentation index at: https://docs.zeotap.com/llms.txt > Use this file to discover all available pages before exploring further. # Calculated Attributes > What a Calculated Attribute is and when to use one. ## What is a Calculated Attribute? A Calculated Attribute is a derived, per-user value that Zeotap computes by aggregating events over a chosen period. It attaches to the customer profile alongside your ingested attributes and updates automatically: batch CAs refresh daily, real-time CAs update as events arrive. Unlike attributes you ingest from a source, a CA is built by the platform from your event data. ## When to use a CA CAs bridge two very different shapes of data. Raw customer events arrive as thousands of separate actions per user; audience conditions need one decision-ready value per user. A CA collapses the events into that single value. For example, `sum_order_value_90d` gives you the total a customer spent in the last 90 days, and a rule like `sum_order_value_90d > 500` defines a High Spenders audience without any raw event data touching the audience builder. ## In this section ## Related Topics