Euro currency guidelines

The following points summarize the guidelines proposed by the European Monetary Union for the euro, which became legal currency on January 1, 1999:

• The conversion rates are expressed as the amount of one euro in terms of each of the national currencies of the participating Member States. They are adopted with six significant figures.
• The conversion rates are rounded or truncated when making conversions.
• Due to the loss of precision that results, you cannot calculate conversions using inverted conversion factors. Conversion to the euro requires division by the legislated conversion factor. Conversion from euro requires multiplication of the same conversion factor.
• Conversions between different currencies of Member States must be done by first converting to the euro and then converting to the other euro-national currency. You cannot derive and use conversion rates between participating national currencies. For example, to convert from Italian lire to French francs you must first convert the Italian lira into euros at the fixed euro/Italian lira rate to at least three decimal places, and then convert the resultant euro amount into French francs at the fixed euro/French franc rate.
• The final result of a conversion into the euro is rounded up or down to the nearest cent. The final result of a conversion into a national currency is rounded up or down to the nearest subunit. In the absence of a subunit, round to the nearest unit or to a multiple or fraction of the unit of the national currency, according to national law. For example, monetary amounts resulting from conversions to French francs may be rounded up or down to the nearest five centimes. If the converted amount is exactly halfway between two of the smallest units, the sum shall be rounded up.