These calculators use the formulas from the 15th Edition of the NFPA Handbook to calculate Theoretical Available Fireflow from a hydrant and the Required Fireflow for a building.

These calculations are commonly used by firefighters when completing Pre-Fire Surveys on target hazards in their districts to determine the flow required to put out a fire in a specified building and the flow actually available from nearby hydrants.

The calculators were created using Microsoft Visual Basic 6. They are both contained in a single application which has been tested on Windows 95, 98, 2000, XP and Vista.