1. What is a CFS to GPM Calculator?

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

Purpose: It helps hydraulic engineers, water resource professionals, and irrigation specialists convert between these common flow rate units.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q_{gpm} \) — Flow rate in gallons per minute
• \( Q_{cfs} \) — Flow rate in cubic feet per second
• 448.83 — Conversion factor (1 ft³/s = 448.83 GPM)

Explanation: The conversion factor comes from the relationship between cubic feet and gallons (7.48052 gallons/ft³) and seconds to minutes (60 s/min).

3. Importance of Flow Rate Conversion

Details: Many engineering specifications use CFS while pump ratings and irrigation systems often use GPM. Accurate conversion ensures proper system design.

4. Using the Calculator

Tips: Simply enter the flow rate in cubic feet per second (CFS). The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the conversion factor 448.83?
A: It's derived from 7.48052 gallons per cubic foot multiplied by 60 seconds per minute (7.48052 × 60 = 448.8312).

Q2: When would I need to convert CFS to GPM?
A: When designing pump systems, specifying irrigation requirements, or interpreting stream flow data for water supply projects.

Q3: How accurate is this conversion?
A: The conversion is mathematically exact. Any inaccuracies would come from measurement errors in the original CFS value.

Q4: Can I convert GPM back to CFS?
A: Yes, divide GPM by 448.83 to get CFS. We may add this reverse calculation in a future update.

Q5: What's a typical CFS value for a small stream?
A: Small streams might range from 0.5 to 10 CFS (224 to 4,488 GPM), while large rivers can exceed 1,000 CFS.