'Fire load' is an accepted concept that captures the complex nature of forest fire management workload. Fire load is defined as 'The number and magnitude (i.e. fire size class and frontal fire intensity) of all fires requiring suppression action during a given period within a specified area' (Merrill and Alexander, 1987). Typically, many management questions are related to fire load rather than to just fire danger or number of fires. For example: - How does this day rank in overall severity? - Was this a 'quiet' (or 'busy') fire season (or month or decade) relative to others? - How does overall spending compare to other similar periods? - There are ten escaped fires and we are expecting 30 new fires daily this week, roughly how many fire crews do we need? The answers to these questions require attention to many variables: the number of fires involved, their size, and the observed or forecast the fire behaviour. Extended suppression efforts on some fires over many days complicates their contribution to fire load. Therefore, the number of new or active fires is a poor measure of workload on one day or fire season. Similarly, final area burned is a poor measure of fire season severity - area burned is an outcome of the interaction of fire load and fire management policy that affects the type and effectiveness of fire response. Fire managers use a number of measures of fire behaviour and fire occurrence to describe fire situations, but they do not have, currently, a commonly accepted and robust single measure of fire load that can be used to describe and compare fire days, seasons, districts, and situations. This paper describes a fire load index that incorporates the fundamental factors of fire activity that represent workload to fire management organizations. The authors have used this fire load index in several situations for comparative analysis and describe the history and context of such indices, and the application of the index in the measurement of program performance, benchmarking studies, and financial analysis.