European size guide charts for men and women are available at SizeGuide.net and About.com. The charts include U.S. sizes, along with their equivalents in the United Kingdom, Italy, France and Germany. A disclaimer on the SizeGuide.net page notes that sizes may vary considerably between manufacturers and brands. The women's charts include conversions for sizes two to 24, while the men's charts have separate tables for suit jacket, pant and dress shirt sizes.
Sizes for women's clothing vary between European countries, so there is no single European size. However, some countries use the same sizing system. Belgium, Spain and Portugal use the same sizes as France does, while Austria, the Netherlands, Switzerland, Sweden, Denmark and Norway use German sizes. British sizes are equivalent to those in Australia and New Zealand.
The men's size charts contain a row that lists a European size; this size covers items from Italy, France, Spain, Germany, Sweden, the Netherlands and Portugal, among others. Men's jackets and pants have their own sizing systems, and men's dress shirt sizes use a measurement of the neck. While American dress shirt sizes also have numbers for the sleeve length, European sizes do not use this measurement, so there is no equivalent.