With the introduction of the new European currency unit, the euro, how do you work with euros in new and existing Microsoft® Excel 97 workbooks? Before you can add the formulas, you must understand the process for the conversion of values. This conversion process includes working with conversion rates, the triangulation method of calculation, and the rounding of values. The Euro - One Currency for Europe Web site provides several European Union publications that describe legal and other issues of concern to those working with the euro.

How values are converted

The euro will eventually replace the national currencies of 11 European countries (additional countries will take part at a later time). The European Union has developed in-depth rules for converting currency values to euros as well as converting values from one currency to another within the Union. Below is a list of key points you should be aware of before you try to convert any existing values to euros by creating formulas in your workbooks.

Conversion rates

On January 1, 1999, the euro became the single currency for the 11 member countries initially adopting the new currency. The national currency of each of these countries is converted to the euro at a fixed rate. Now that these rates have been determined, they can be applied in calculations for converting values to euros. For precise calculations, conversion rates use six significant digits. Review Euro Paper 17 and Euro Paper 22 at The Euro - One Currency for Europe site for more information.

Triangulation

The triangulation method is used to convert one currency to another by using an intermediary currency. Now that the euro has been introduced, this process will be used for accurate conversions. For example, to convert French francs to Dutch guilders, you must convert the francs to euros first, and then convert the euros to guilders. However, there are additional rules that apply to conversions using the triangulation method. You can read more about the process in Euro Paper 21 at The Euro - One Currency for Europe site.

Rounding

When converting values, you must be very careful how you round them. Excel automatically rounds the values that are displayed on screen according to formatting rules. For example, if a cell contains the value 2.596 and is formatted as dollars, it will appear as $2.60 and not $2.59. If this cell is used in any calculation, the value 2.596 is used, not 2.60.

For euro conversions, rounding is quite important. The amount that values are rounded depends upon the type of conversion that is taking place. For information about the rounding rules for the euro, read Euro Papers 4, 21, and 22 at The Euro - One Currency for Europe site.

Note  Excel includes worksheet functions that round numbers. The most common one - the ROUND worksheet function - rounds numbers up or down. For information about the ROUND function, see Excel Help.

You can read more about the euro at the Microsoft euro currency resource center .