The international standard procedure for testing solar cookers and reporting performance was proposed at the Third World Conference on Solar Cooking (Avinashilingam University, Coimbatore, India, 6-10 January, 1997) and revised by the committee over the following months. The standard sets limits for environmental conditions, specifies test procedures and calls for performance to be reported in terms of cooking power (W). While this value, like the fuel economy rating of an automobile, is not a guarantee of performance, it does provide a useful tool for comparison. The entire standard is presented in this paper. It was evaluated both by using ii to analyze data previously collected and by using it to test one of the solar cookers in the historical data set. The rest standard cooking power curve clearly distinguishes between solar cookers of differing design. Estimates of solar cooker performance for different locations and dates are fairly consistent when the test standard is employed. The criteria of being easy to use and presenting data predictive of thermal performance are also satisfied.