Sprinkler K-Factor Solver
Solve Q = K x sqrt(P) for flow, pressure, or K-factor.
Example
You enter
- Solve for flow
- K-factor (nameplate) 5.6
- Pressure (psi) 7
You get
- Flow (GPM) 14.82
Checked against published worked examples from: NFPA 13 (sprinkler discharge relation).
Details, formula, and sources
ScopePer NFPA 13; complements the design-density calculation.
Formula or tableQ = K * sqrt(P), solved for flow Q (gpm), pressure P (psi), or the nominal nameplate K-factor.
Source and editionNFPA 13 sprinkler discharge relation Q = K*sqrt(P), by name.
Free accessFree read-only at nfpa.org/freeaccess; NFPA 13 governs the design.
What governsEstimate. AHJ and licensed fire protection engineer govern.
API field namessolve_for, k_factor, pressure_psi, flow_gpm
- K-factor nominal nameplate K (e.g., 5.6 for a standard 1/2-in orifice); the actual K is marked on the sprinklerNFPA 13 / manufacturer data sheet