"The student will learn two fire flow formulas that Incident Commanders (ICs) can use in their size-up to compute flow demands. There are at least five recognized fire flow calculation methods currently in use. Some are intended for preincident assessment of a community's flow rate; others are quick calculations for ICs who are faced with an emergency. The 'community flow rate' calculations generally are meant for conflagration control rather than for a building fire or single room-and-contents event."
Coffee Break Training - Fire Protection Series No. FP-2013-38
United States Fire Administration: http://www.usfa.fema.gov/