Fire Flow Calculator

Formulas

The formulas to calculate the required fire flow are:

ISU Method:

\[ RFF = \frac{V}{100} \]

NFA Method:

\[ RFF = \frac{L \times W}{3} \]

Where:

\(RFF\) is the required fire flow (GPM)
\(V\) is the volume (square feet)
\(L\) is the length (feet)
\(W\) is the width (feet)

Fire Flow Definition

Fire flow is a measure of the total rate of water flow required to suppress a fire. Fire flow is most often expressed in gallons per minute. It’s often used as a rough estimate as opposed to an exact measure.

Example Calculation

Let's assume the following values:

Length (L) = 30 feet
Width (W) = 20 feet
Volume (V) = 600 square feet (optional for ISU Method)

Using the NFA Method:

\[ RFF = \frac{30 \times 20}{3} = 200 \text{ GPM} \]

The Required Fire Flow (RFF) is 200 GPM.

Using the ISU Method:

\[ RFF = \frac{600}{100} = 6 \text{ GPM} \]

The Required Fire Flow (RFF) is 6 GPM.