# CalculatedColumnType

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

Wizard / evaluation category for a Calculated Column.

- `Standard` — per-row value from other cells in the row (`[price] * [qty]`)
- `Observable` — per-row value from the row's **change history**
 (`CHANGE_COUNT{[price], WITHIN(5m)}`, `[price] - PREVIOUS{[price]}`,
 `ROW_AGE{}`); refreshes on data changes and as time windows expire
- `Aggregated` / `Cumulative` / `Quantile` / `Window` — value over a set of rows

The type is an authoring lens (wizard card, editor flavour, examples);
evaluation follows the expression's  — see
.

Stored on . When `Type` is omitted it is inferred from .

```ts title="TypeScript"
export type CalculatedColumnType = 'Standard' | 'Observable' | 'Aggregated' | 'Cumulative' | 'Quantile' | 'Window';
```