The flow test calculator in the FireDash app turns field gauge readings into flow numbers using standard NFPA 291 flow-test math.
What you enter
- Static pressure — system pressure with no flow.
- Residual pressure — pressure during the flow.
- Pitot (nozzle) pressure — at the flowing outlet.
- Outlet diameter and outlet type — smooth and rounded, square and sharp, or protruding (the type sets the discharge coefficient).
- Hydrant capacity — the rated reference for percent-capacity.
What you get
- Test flow (GPM) from the flowing outlet.
- Recommended flow at 20 PSI residual — the available fire flow.
- Nozzle reaction in pounds and percent of capacity.
- The standard NFPA 291 color class: Class AA (1,500+ GPM, light blue), Class A (1,000–1,499, green), Class B (500–999, orange), Class C (under 500, red).
Tap the info icon next to any field in the app for a plain-language explanation of that reading.