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Tool

End Head Pressure Calculator

Find the flow at a sprinkler head from density and area, then look up the pressure required for standard K-factors or enter a custom K-factor.

Find End Head Pressure

Calculate sprinkler flow from density and area, then find the pressure required for standard and custom K-factors.

Calculated flow

25.6 GPM

0.1 density × 256 sq. ft.

Flow Calculation

Enter the desired density for your calculation.

Enter the coverage area for a single sprinkler.

Custom K-Factor

Enter a custom K-factor and the psi will be calculated. This is primarily for residential sprinklers.

Custom result

19.48 psi

at K 5.8 · 25.6 GPM

Engineering disclaimer

Results are for preliminary engineering only. Final designs must be reviewed by a licensed fire protection engineer and verified against NFPA 13/14 and the local AHJ.

Standard K-Factor Pressures

Pressure required to deliver the calculated flow for standard K-factors used in commercial and storage applications.

10 K-factors
K-factorpsi
2.883.59 psi
4.237.15 psi
5.620.90 psi
810.24 psi
11.25.22 psi
143.34 psi
16.82.32 psi
25.21.03 psi
280.84 psi
34.60.55 psi
psi = (flow ÷ K-factor)²

Nearest standard K: 5.6