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

# Apply Country Transform

> Country-specific unit conversions — constant prices, per capita, % of GDP and currency conversion — with explicit control over which country applies.

The **Apply Country Transform** step performs the unit conversions that depend on a country's reference data: inflation indices for constant prices, population for per capita, GDP series for shares of GDP, and exchange rates for currency conversion.

It is the same engine as [Apply Transform](/steps/transform), narrowed to country-dependent conversions and with explicit control over **which country** the reference data comes from.

## Configuration

The step detects the input frequency and offers only the conversions valid for it.

<Frame>
  <img src="https://mintcdn.com/alphacastio/ttF_U-V9HDrmrPbo/images/steps/change-units-config.png?fit=max&auto=format&n=ttF_U-V9HDrmrPbo&q=85&s=bcd4b4ebad0cc71e5a91110624291883" alt="Apply Country Transform step with the transformation, country column and column selector" width="1561" height="693" data-path="images/steps/change-units-config.png" />
</Frame>

| Field          | Description                                                                                           |
| -------------- | ----------------------------------------------------------------------------------------------------- |
| Transformation | Which conversion to apply. The options depend on the detected frequency.                              |
| Country column | The column holding country values. Defaults to a column named `country` or `Country` when one exists. |
| Country        | A fixed country, used instead of a column when the dataset has no country entity.                     |
| Columns        | The columns to convert. Use **Select all** / **Clear selection** for bulk changes.                    |

<Note>
  This is the step's distinguishing feature. [Apply Transform](/steps/transform) requires the dataset to carry a country entity; here you can point at any column, or declare a single country outright — which is what makes these conversions possible on datasets that never named a country in the first place.
</Note>

## Available conversions

<AccordionGroup>
  <Accordion title="Daily data">
    | Transformation                                 |
    | ---------------------------------------------- |
    | Currency conversion LCU / USD - daily          |
    | Currency conversion BCS / USD (Argentina only) |
  </Accordion>

  <Accordion title="Monthly data">
    | Transformation                                 |
    | ---------------------------------------------- |
    | Constant prices                                |
    | Per Capita                                     |
    | % of GDP                                       |
    | % of USD GDP                                   |
    | Sum last 12 months - % of GDP                  |
    | Currency conversion LCU / USD - monthly        |
    | Currency conversion BCS / USD (Argentina only) |
  </Accordion>

  <Accordion title="Quarterly data">
    | Transformation                                 |
    | ---------------------------------------------- |
    | Constant prices                                |
    | Per Capita                                     |
    | % of GDP                                       |
    | Currency conversion LCU / USD - quarterly      |
    | Currency conversion BCS / USD (Argentina only) |
  </Accordion>

  <Accordion title="Yearly data">
    | Transformation                                 |
    | ---------------------------------------------- |
    | Constant prices                                |
    | Per Capita                                     |
    | % of GDP                                       |
    | % of Current USD GDP                           |
    | Currency conversion LCU / USD                  |
    | Currency conversion BCS / USD (Argentina only) |
  </Accordion>
</AccordionGroup>

Each conversion pulls its reference series from Alphacast automatically — the step shows which auxiliary datasets it is using once you pick a transformation.

## Next steps

<CardGroup cols={2}>
  <Card title="Apply Transform" icon="wand-magic-sparkles" href="/steps/transform">
    The full transformation set, including changes and moving averages.
  </Card>

  <Card title="Validate Countries" icon="globe" href="/steps/country-validator">
    Harmonize country names so the reference data matches.
  </Card>
</CardGroup>