# inferCalculatedColumnTypeFromExpression

Canonical page: https://www.adaptabletools.com/docs/reference/infercalculatedcolumntypefromexpression

Infer  from the expression text: an aggregated
category (Aggregated / Cumulative / Quantile / Window) when it contains an
aggregation, `Observable` when it is per-row and contains an observable
brace call (`CHANGE_COUNT{…}`, `ROW_AGE{}`, …), otherwise `Standard`.
Runtime fallback when `Type` is absent.

```ts title="TypeScript"
inferCalculatedColumnTypeFromExpression: (expression: string | undefined | null) => CalculatedColumnType
```