Air Flow Rate Calculator CFM

Flow Rate Conversion Formula:

\[ Q_{cfm} = Q_{gpm} \times 7.481 \]

Flow Rate (CFM):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is an Air Flow Rate Calculator CFM?

Definition: This calculator converts flow rate from gallons per minute (GPM) to cubic feet per minute (CFM).

Purpose: It helps HVAC professionals, engineers, and technicians convert between these common flow rate units.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q_{cfm} = Q_{gpm} \times 7.481 \]

Where:

\( Q_{cfm} \) — Flow rate in cubic feet per minute
\( Q_{gpm} \) — Flow rate in gallons per minute
7.481 — Conversion factor (gallons per cubic foot)

Explanation: Since there are 7.481 gallons in a cubic foot, multiplying GPM by this factor converts to CFM.

3. Importance of Flow Rate Conversion

Details: Accurate flow rate conversion is essential for proper system design, performance evaluation, and equipment selection in HVAC and fluid systems.

4. Using the Calculator

Tips: Simply enter the flow rate in gallons per minute (GPM). The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is 7.481 the conversion factor?
A: There are exactly 7.48052 gallons in one cubic foot (rounded to 7.481 for practical calculations).

Q2: When would I need to convert GPM to CFM?
A: When working with systems that use different units or when comparing specifications that use different measurement systems.

Q3: Is this conversion affected by temperature or pressure?
A: No, this is a straightforward volume conversion. For mass flow rates or at extreme conditions, additional factors may be needed.

Q4: Can I convert CFM back to GPM?
A: Yes, by dividing CFM by 7.481 (GPM = CFM / 7.481).

Q5: What's a typical GPM value for residential HVAC?
A: Typical values range from 5-20 GPM depending on system size, which converts to 37-150 CFM.