> ## 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.

# FAQs about Calculated Attributes

> Short answers to the questions we are asked most often about Calculated Attributes.

Each answer links to the page that covers the topic in full.

<AccordionGroup>
  <Accordion title="How many calculated attributes can I create?">
    As many as your pricing package allows, and this allowance is separate from your limit on other attribute types. To create more than your package permits, contact your Customer Success Manager. See [Calculated Attributes: Guardrails & Limits](/articles/unify-customer/calculated-attributes-guardrails-and-limits).
  </Accordion>

  <Accordion title="Where can I use calculated attributes?">
    In Audiences as segmentation criteria, in Journeys, to filter users and events from a real-time streaming source, and through the Profile API. See [How Calculated Attributes Work](/articles/unify-customer/how-calculated-attributes-work) and [Calculated Attributes: Use Cases](/articles/unify-customer/calculated-attributes-use-cases).
  </Accordion>

  <Accordion title="How can I see or validate calculated attributes?">
    Calculated attribute values are not currently shown per-user in the CDP UI. Build a small test audience with a rule on the attribute and validate the count matches your expectation, or contact your Zeotap representative to verify specific values. See [Guardrails & Limits: validation and visibility](/articles/unify-customer/calculated-attributes-guardrails-and-limits#validation-and-visibility).
  </Accordion>

  <Accordion title="How frequently does a calculated attribute get refreshed?">
    Batch attributes in the active state refresh daily, and paused attributes are not refreshed. Real-time attributes update as events arrive. See [Guardrails & Limits: refresh and freshness](/articles/unify-customer/calculated-attributes-guardrails-and-limits#refresh-and-freshness).
  </Accordion>

  <Accordion title="After a user performs an event, how long does it take for the corresponding calculated attributes to get refreshed?">
    Usually 24 to 36 hours, and around 72 hours in the worst case, because ingestion and the attribute refresh are two separate delays. See [Guardrails & Limits: refresh and freshness](/articles/unify-customer/calculated-attributes-guardrails-and-limits#refresh-and-freshness).
  </Accordion>

  <Accordion title="How far back can a calculated attribute look?">
    When you select **over the last** as the run computation, batch attributes support up to 540 days or 18 months. Real-time attributes support up to one month, expressed as 30 days or 4 weeks, and up to 24 hours where the window is hourly. Selecting **over entire data** computes across all of your data with no window limit. See [Guardrails & Limits](/articles/unify-customer/calculated-attributes-guardrails-and-limits).
  </Accordion>

  <Accordion title="Why does my rule 'CA = 0' match no users?">
    `{{VERIFY WITH PM: confirm users with no qualifying events hold no value rather than 0, and state the correct way to target them}}` See [Guardrails & Limits: users with no qualifying events](/articles/unify-customer/calculated-attributes-guardrails-and-limits#users-with-no-qualifying-events).
  </Accordion>

  <Accordion title="Can I edit or delete a CA after creating it?">
    `{{VERIFY WITH PM: whether editing recomputes history or applies going forward only, and what happens to audiences or journeys using an attribute that is deleted}}` See [Guardrails & Limits: editing, pausing, and deleting](/articles/unify-customer/calculated-attributes-guardrails-and-limits#editing-pausing-and-deleting).
  </Accordion>

  <Accordion title="How do I know if my CA is stale or failing?">
    Check the **Status** and **Last Successful Refresh** columns on the Calculated Attributes screen. See [Components of the Calculated Attributes Screen](/articles/unify-customer/components-of-the-calculated-attributes-screen) and [Calculated Attributes: Guardrails & Limits](/articles/unify-customer/calculated-attributes-guardrails-and-limits).
  </Accordion>
</AccordionGroup>