Reference table

Fire Sprinkler K-Factor Table

Name: Fire Sprinkler K-Factor Table
Keywords: sprinkler K-factor table

Reference common sprinkler K-factor values used for quick flow and pressure checks in NFPA 13 style sprinkler calculations.

sprinkler K-factor table9 rows2 linked calculators

Rows

Reference values

Columns

Lookup fields

Linked tools

Calculators using this data

Page role

Use this page for a defined task before moving to the next project record.

Audience: Engineers, designers, reviewers, and technicians selecting calculator input values.
Job: Use this table when a sprinkler discharge check needs the listed K-factor before solving flow, pressure, or minimum flow.
Evidence: Match the listed sprinkler K-factor from product data before using a table row. Do not choose a larger K-factor only to reduce required pressure unless the sprinkler listing and design basis support it.
Output: Selected Standard K-Factors row carried into 2 calculator workflows.
Next: Choose the matching row, review selection checks, then open the calculator or worksheet that consumes the value.

Source governance

Record how this table is used before carrying a value into a calculator, worksheet, or authority workflow.

Governance item	Record	Use boundary
Source class	Engineering lookup table	Use the table as a controlled reference input, not as an adoption or approval database.
Last review basis	Static registry review	Re-check adopted standards, manufacturer data, and project criteria before final use.
Known limit	Manufacturer data, adopted edition, and project specifications can supersede a generic reference row.	Escalate unresolved code, listing, or jurisdiction questions to the project record.
Downstream record	Sprinkler K-Factor Flow and Pressure Calculator, Sprinkler System Demand Calculator, NFPA 13 Hydraulic Design Worksheet, Hazard Classification and Density Setup Worksheet	Keep selected rows with the worksheet, calculation package, or authority record.

Reference table structure

Use these fields to filter the table, select a value, and retain the basis with the calculation record.

Rows

Filter fields

K-Factor

Value columns

Typical Use, Numeric K

Table area	Values	Engineering use
Query examples	K-Factor = K2.8; K-Factor = K5.6; K-Factor = K8.0	Use these values as table filters before carrying a row into a calculator.
Related calculators	Sprinkler K-Factor Flow and Pressure Calculator, Sprinkler System Demand Calculator	Selected rows become calculation inputs or reasonableness checks for the linked tools.
Related worksheets	NFPA 13 Hydraulic Design Worksheet	Worksheet records preserve the selected value with the project assumption trail.

Reference table use

Use the table as controlled input data: select the row, verify the condition, and carry the value to the related calculator.

Usage context

1Use this table when a sprinkler discharge check needs the listed K-factor before solving flow, pressure, or minimum flow.
2Treat the K-factor as sprinkler-specific input from the product data or design basis, not a generic occupancy value.
3Carry the selected K-factor into discharge, coverage, density-area, and hydraulic worksheet checks.

Selection rules

1Match the listed sprinkler K-factor from product data before using a table row.
2Do not choose a larger K-factor only to reduce required pressure unless the sprinkler listing and design basis support it.
3When coverage or storage criteria control sprinkler selection, confirm the K-factor with the selected sprinkler model.

Review checks

1Selected K-factor matches the listed sprinkler basis used for the discharge point.
2Pressure and flow are solved for the same sprinkler and not mixed with pump discharge pressure.
3Coverage, density, and minimum-flow checks are reviewed before relying on the discharge result.

Reference field	How to use it	Related tools
K-Factor	Use this field to identify the matching project condition.	Sprinkler K-Factor Flow and Pressure Calculator, Sprinkler System Demand Calculator, NFPA 13 Hydraulic Design Worksheet
Typical Use	Carry this value into the downstream calculator with the displayed units and label.	Sprinkler K-Factor Flow and Pressure Calculator, Sprinkler System Demand Calculator, NFPA 13 Hydraulic Design Worksheet
Numeric K	Carry this value into the downstream calculator with the displayed units and label.	Sprinkler K-Factor Flow and Pressure Calculator, Sprinkler System Demand Calculator, NFPA 13 Hydraulic Design Worksheet

Selection examples

Use these examples to choose a row deliberately before carrying the value into a calculator or worksheet.

Scenario	Row choice	Reason	Downstream use
A standard spray sprinkler submittal lists K5.6 for the selected model.	Use the K5.6 sprinkler row only when it matches the listed model and orientation.	K-factor is a sprinkler discharge coefficient, not a generic hazard-class value.	Carry K5.6 into the sprinkler K-factor calculator with pressure at the sprinkler and the coverage basis.
A designer wants lower required pressure at a remote sprinkler.	Compare a larger K-factor only after confirming the alternate sprinkler is listed for the application.	A larger K-factor changes the selected sprinkler and may affect spacing, coverage, and listing constraints.	Use the row as an option screen, then update the density-area and hydraulic worksheet if the sprinkler changes.
Coverage area requires more flow than a small K-factor provides at available pressure.	Keep the actual listed K-factor row and flag the pressure or sprinkler selection problem.	Changing the table row without changing the sprinkler would hide a real design constraint.	Send the result to coverage, density-area, and system-demand review before final sprinkler selection.

Checking K-factor against sprinkler coverage

Assumptions

1A remote sprinkler is selected from product data with K5.6.
2The preliminary pressure at the sprinkler is 12 psi.
3The coverage and design density require the discharge result to be reviewed before hydraulic handoff.

Steps

1Select the K5.6 row because it matches the listed sprinkler model.
2Run the K-factor calculator using pressure at the sprinkler, not pump discharge pressure.
3Compare calculated flow against the coverage-area demand for the same sprinkler.
4If the flow is short, revisit pressure, spacing, or sprinkler model instead of changing the reference row silently.

Result

The workpaper shows whether the selected sprinkler can support the coverage basis. The K-factor row remains tied to the product data and does not change unless the sprinkler selection changes.

Misuse warnings

1Do not use a K-factor row that does not match the listed sprinkler model being reviewed.
2Do not change K-factor only to make pressure look acceptable without changing the sprinkler selection and listing basis.
3Do not judge sprinkler adequacy from K-factor alone without coverage, density, and minimum-flow review.

Standard K-Factors

K-Factor	Typical Use	Numeric K
K2.8	Small orifice	2.8
K5.6	Standard spray	5.6
K8.0	Large orifice	8
K11.2	Extended coverage	11.2
K14.0	ESFR / storage	14
K16.8	Large drop / storage	16.8
K22.4	High-flow storage	22.4
K25.2	High-flow storage	25.2
K28.0	High-flow storage	28

Engineering disclaimer

NFPA in USA provides engineering workpapers, calculation checks, and reference tables for project screening and coordination. Final design decisions, code interpretations, submittals, and acceptance records must be completed by qualified professionals and verified against the adopted code, project criteria, listings, and Authority Having Jurisdiction requirements. This site does not issue signed or sealed engineering documents.

Tools and workflows that use this table

Sprinkler K-Factor Flow and Pressure Calculator Sprinkler System Demand Calculator NFPA 13 Hydraulic Design Worksheet Hazard Classification and Density Setup Worksheet

FAQ

How should this K-factor table be used?+

Use it as an engineering reference source for selecting values, checking assumptions, and documenting the basis carried into a calculator or worksheet.

Can this table replace the sealed project record?+

No. Values still need to be checked against the adopted standard, manufacturer data, project specifications, and Authority Having Jurisdiction requirements before they are used in final documents.