Quantity of Water by Freeman's Formula Calculator

Freeman's Formula:

\[ Q = 1136 \times \left(\frac{P}{5} + 10\right) \]

Water Quantity (Liters Per Minute):

1. What is Freeman's Formula Calculator?

Definition: This calculator estimates the quantity of water required for firefighting based on population using Freeman's formula.

Purpose: It helps municipal planners and fire departments determine water supply requirements for fire protection.

2. How Does the Calculator Work?

The calculator uses Freeman's formula:

\[ Q = 1136 \times \left(\frac{P}{5} + 10\right) \]

Where:

\( Q \) — Quantity of water (liters per minute)
\( P \) — Population (in thousands)

Explanation: The formula calculates the required fire flow based on the population served, with a minimum base requirement.

3. Importance of Water Quantity Calculation

Details: Proper water quantity estimation ensures adequate fire protection, proper hydrant sizing, and municipal water system planning.

4. Using the Calculator

Tips: Enter the population in thousands (e.g., 20 for 20,000 people). The result has a ±5% margin of error.

5. Frequently Asked Questions (FAQ)

Q1: Why does the formula use population?
A: Fire risk correlates with population density and building density, which Freeman's formula accounts for.

Q2: What's the ±5% margin for?
A: It accounts for variations in local conditions, building types, and fire risk factors.

Q3: Is this formula used worldwide?
A: Primarily in North America, though similar formulas exist elsewhere with different coefficients.

Q4: When was Freeman's formula developed?
A: It was developed in the early 20th century by John R. Freeman, a hydraulic engineer.

Q5: Does this include domestic water needs?
A: No, this calculates only fire protection requirements. Domestic needs must be calculated separately.