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

# $avg

`$avg` computes the arithmetic mean of a field across matching documents.

If `missing` is provided, documents without the field are treated as if they had the `missing` value.

### Compatibility

| Field Type  | Supported |
| ----------- | --------- |
| TEXT        | No        |
| U64/I64/F64 | Yes       |
| DATE        | Yes       |
| BOOL        | Yes       |
| KEYWORD     | No        |
| FACET       | No        |

Field must be `FAST`.

### Arguments

| Argument  | Type     | Required | Description                        |
| --------- | -------- | -------- | ---------------------------------- |
| `field`   | `string` | Yes      | Field to aggregate.                |
| `missing` | `number` | No       | Fallback value for missing fields. |

<Tabs>
  <Tab title="TypeScript">
    ```ts theme={"system"}
    await index.aggregate({
      aggregations: {
        avg_price: { $avg: { field: "price", missing: 0 } },
      },
    });
    ```
  </Tab>

  <Tab title="Python">
    ```python theme={"system"}
    index.aggregate(
        aggregations={"avg_price": {"$avg": {"field": "price", "missing": 0}}}
    )
    ```
  </Tab>

  <Tab title="Redis CLI">
    ```bash theme={"system"}
    SEARCH.AGGREGATE products '{}' '{"avg_price": {"$avg": {"field": "price", "missing": 0}}}'
    ```
  </Tab>
</Tabs>

### Output

```json theme={"system"}
{ "avg_price": { "value": 40 } }
```

`value` is `null` when no values are available after filtering.