As foreign companies are added to the Calcbench database we compute standardized metrics in USD even if their original financial statements are filed in another currency. The conversion is done the following way:
For balance sheet items (instant items) we use the exchange rate closest to the end of the fiscal period filed.
For income statement items (period items) we use an average of all available exchange rates for the fiscal period filed.
You can get the associated metrics:
primary_currency - for the original currency used in the report.
exchange_rate_duration - the exchange rate for income statement or period items.
exchange_rate_instant - the exchange rate for balance sheet or instant items.
All exchange rate data is sourced from Federal Reserve Economic Data (FRED) (https://fred.stlouisfed.org/)