K-Factor Calculator
Q = K × √P — Solve for any variable
How to use this tool:
- Choose what to solve for — K-factor, flow (Q), or pressure (P)
- Enter the two known values
- Read the result — or click a row in Common K-Factors below to fill a standard head
What do you want to calculate?
Flow (Q)
Volume per time
Pressure (P)
Operating pressure
K-Factor (K)
Device constant
Result
—
CALCULATION
Enter values above to calculate
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Common K-Factors
Click a row to use that K-factor in the calculator
| Device Type | K (L/min/√bar) | K (GPM/√PSI) |
|---|---|---|
| Standard Sprinkler (K5.6) | 80.73 | 5.6 |
| Standard Sprinkler (K8.0) | 115.33 | 8.0 |
| Large Orifice Sprinkler (K11.2) | 161.46 | 11.2 |
| ESFR Sprinkler (K14.0) | 201.83 | 14.0 |
| ESFR Sprinkler (K16.8) | 242.20 | 16.8 |
| ESFR Sprinkler (K19.6) | 282.56 | 19.6 |
| ESFR Sprinkler (K22 = K22.4) | 322.93 | 22.4 |
| ESFR Sprinkler (K25.2) | 363.29 | 25.2 |
| ESFR Sprinkler (K28.0) | 403.66 | 28.0 |
| ESFR Sprinkler (K32 = K33.6) | 480.0 | 33.6 |
K-factor conversion: Kmetric = Kimperial × 14.4164.
Nominal head names are rounded: a “K22” head is actually K22.4, a “K32” ESFR is actually K33.6 (mfr rating 480). Beware datasheets that round metric K (e.g. K320) — they under-read flow ~1% and can flip a pass/fail.
Nominal head names are rounded: a “K22” head is actually K22.4, a “K32” ESFR is actually K33.6 (mfr rating 480). Beware datasheets that round metric K (e.g. K320) — they under-read flow ~1% and can flip a pass/fail.
Standards Reference
AS 2118.1 — Automatic fire sprinkler systems
NFPA 13 — Standard for the Installation of Sprinkler Systems
We provide no warranty or guarantee for the use of this tool or its accuracy. In no event will we be liable for any loss or damage, including, without limitation, indirect or consequential loss or damage, or any loss or damage arising from loss of data or profits arising out of, or in connection with, the use of this tool.