🚿 gal/min to ft³/s — Gallon/Minute (US) to Cubic Foot/Second Converter

Convert flow rate units — m³/s, L/s, L/min, ft³/s, gallon/min and more.

1 unit =
From
To
Formula 1 GPM = 0.002228 ft³/s
UnitNameValue
m³/s Cubic Meter/Second 0.00006309
m³/min Cubic Meter/Minute 0.0037853243
m³/h Cubic Meter/Hour 0.22694245
L/s Liter/Second 0.06309
L/min Liter/Minute 3.7853243
ft³/s Cubic Foot/Second 0.0022279903
ft³/min Cubic Foot/Minute 0.13366525
gal/h Gallon/Hour (US) 60

Quick Answer

Formula: ft³/s = GPM × 0.002228

Multiply any GPM value by 0.002228 to get ft³/s.

Reverse: GPM = ft³/s × 448.8

Worked Examples

1 ft³/s
448.8 GPM × 0.002228 = 0.9999 ft³/s
448.8 GPM = 1 ft³/s.
0.00223 ft³/s
1 GPM × 0.002228 = 0.002228 ft³/s
1 GPM = 0.00223 ft³/s.
0.033 ft³/s
15 GPM × 0.002228 = 0.03342 ft³/s
15 GPM = 0.033 ft³/s — home pump.
1.114 ft³/s
500 GPM × 0.002228 = 1.114 ft³/s
500 GPM = 1.114 ft³/s — hydrant.

GPM to ft³/s Conversion Table

Common flow rate values — factor: 1 GPM = 0.002228 ft³/s

GPM (GPM)ft³/s (ft³/s)Context
0.01 GPM2.228e-05 ft³/sDrip
0.1 GPM0.0002228 ft³/sSlow drip
1 GPM0.002228 ft³/s1 GPM
5 GPM0.01114 ft³/sResidential pump
10 GPM0.02228 ft³/sGarden irrigation
15 GPM0.03342 ft³/sHome well pump
100 GPM0.2228 ft³/sLight commercial
500 GPM1.114 ft³/sFire hydrant small
1000 GPM2.228 ft³/sFire hydrant
5000 GPM11.14 ft³/sLarge system
1e+04 GPM22.28 ft³/sMunicipal pump
5e+04 GPM111.4 ft³/sLarge plant
1e+05 GPM222.8 ft³/sVery large
1e+06 GPM2228 ft³/sExtreme
1e+07 GPM2.228e+04 ft³/sMax

Mental Math Tricks

÷ 448.8

GPM ÷ 448.8 = ft³/s.

Key anchor

448.8 GPM = 1 ft³/s.

Reverse

ft³/s × 448.8 = GPM.

Who Uses This Conversion?

Hydraulic Engineer

Designs pumps, pipes, and water distribution systems with flow rates in m³/s, L/s, and GPM.

HVAC Engineer

Specifies air handling units and ductwork in CFM (ft³/min) and m³/h for North American and European projects.

Water Treatment Plant Operator

Monitors and controls treatment processes with flow rates in m³/h, L/s, and MGD.

Fire Protection Engineer

Designs sprinkler systems with required flows in GPM and L/min per NFPA standards.

Hydrologist

Measures river and groundwater flows in m³/s (m) and ft³/s (cfs) for flood modeling and water resource planning.

Medical Equipment Technician

Configures ventilators and oxygen delivery systems with flow rates specified in L/min.

Frequently Asked Questions

About GPM and ft³/s

GPM (GPM)

Gallons per minute (GPM) is the standard flow unit for pumps, plumbing, fire suppression, and irrigation systems in the United States. One US GPM = 6.309 × 10⁻⁵ m³/s = 3.785 L/min.

US pump specifications universally use GPM: a residential well pump delivers 5–20 GPM; a fire suppression sprinkler system requires 7–26 GPM per head; a municipal fire hydrant delivers 500–1,500 GPM. Fuel transfer pumps at gas stations operate at 10–15 GPM.

Interesting fact: The US uses about 345 billion gallons of freshwater per day — approximately 240 million GPM. Of this, about 41% goes to thermoelectric power plant cooling, 37% to irrigation, and 13% to public water supplies.

ft³/s (ft³/s)

Cubic feet per second (ft³/s), also called cusecs, is the standard volumetric flow unit for rivers and streams in the United States. One ft³/s = 0.028317 m³/s ≈ 28.32 L/s.

US Geological Survey (USGS) stream gauges report flow in ft³/s (cfs). Irrigation water rights, hydropower licensing, and environmental flow requirements in the US are expressed in cfs. The Colorado River at Hoover Dam averages about 7,500 cfs.

Interesting fact: During Hurricane Harvey (2017), some Houston streams exceeded 400,000 cfs — more than 10 times the normal peak flow. The USGS maintains over 8,000 stream gauges across the US, all reporting in cfs.

About GPM to ft³/s Conversion

Converting GPM to ft³/s is essential across hydraulic engineering, HVAC, water treatment, fire protection, and medicine. SI units (m³/s, L/s) are standard in science; European engineering uses m³/h; US systems use GPM and CFM; medical applications use L/min.

Quick reference: 10 GPM = 0.02228 ft³/s. Reverse: 1 ft³/s = 448.8 GPM. Factor: 1 GPM = 0.002228 ft³/s.

All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.