CFS to GPM Conversion Calculator

Last updated: 20 Jul 2025 | Author: Brij | Review By: Irshad

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Convert Cubic Feet per Second (CFS) to Gallons per Minute (GPM) instantly using our CFS to GPM Calculator. Ideal for engineers, irrigation, and plumbing professionals.

Flow Rate:

Flow Rate Conversion Results

Cubic Feet per Second (CFS):

ft³/s

Gallons per Minute (GPM):

gal/min

Flow rate is one of the most critical measurements in fluid engineering, plumbing, irrigation, and construction-related water systems. When working with pipes, channels, or pumps, you’ll often need to convert Cubic Feet per Second (CFS) to Gallons per Minute (GPM) — two commonly used flow rate units in the U.S.

Our CFS to GPM Conversion Calculator helps you quickly and accurately convert these units with ease.

What is CFS and GPM?

CFS (Cubic Feet per Second) is a unit of flow rate used to measure the volume of fluid passing through a point every second in cubic feet. Common in hydrology and civil engineering.
GPM (Gallons per Minute) measures how many U.S. gallons of fluid pass a point per minute. Widely used in plumbing, water supply systems, and irrigation.

CFS to GPM Conversion Formula

To convert CFS to GPM, use the following formula:

$\text{GPM} = \text{CFS} \times 448.831$

Where:

1 cubic foot = 7.48052 gallons
1 minute = 60 seconds
So, $1 \, \text{CFS} = 7.48052 \times 60 = 448.831 \, \text{GPM}$

Example –

CFS to GPM Conversion

Let’s say you have a flow rate of 2.5 CFS, and you want to convert it to GPM.

$\text{GPM} = 2.5 \times 448.831 = 1,122.0775 \, \text{GPM}$

So, 2.5 CFS is approximately 1,122.08 GPM.

GPM to CFS Conversion Formula

If you want to convert back from GPM to CFS, simply divide by 448.831:

$\text{CFS} = \frac{\text{GPM}}{448.831}$

Example (Reverse):

If you have 2,000 GPM:

$\text{CFS} = \frac{2000}{448.831} \approx 4.46 \, \text{CFS}$

Why Is This Conversion Important?

This conversion is critical in:

Designing irrigation systems
Sizing water pumps
Stormwater drainage planning
Hydraulic modeling in civil engineering
Water treatment plant flow measurements

Many times, engineers receive data in CFS but need to work with pumps and flow meters rated in GPM — or vice versa.

Final Thoughts

Flow rate conversion plays a key role in designing reliable and efficient fluid systems. With our CFS to GPM Conversion Calculator, you’ll never need to manually multiply or divide again — just enter your value, and get accurate results in seconds.

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