This paper provides a detailed procedure for applying similitude (dimensional analysis) to engineering problems where there is not enough information for an analytical solution. Similitude allows the investigator to use experimental data to develop empirical prediction equations relating the parameters involved. Two examples illustrate the entire procedure. One is a four-pi-term problem and the other is an eight-pi-term. Both problems have exact analytical solutions, and the original data were computed analytically. This approach allows direct comparison of results obtained from the empirical equations with exact solutions.