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Volume Flow Rate Converter

Convert fluid pumping volumes and ventilation airflow across m³/s, m³/h, L/s, L/min, CFM (ft³/min), and US GPM with real-time bidirectional calculations.

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Instant pair conversions with verified scientific and mathematical formulas

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1 L/min = 0.26417 GPM

GPM (US) to L/min→

1 GPM = 3.78541 L/min

Volume Flow Rate Reference Equivalents (1 Cubic meter per second)

Standard ratios measured against the base Cubic meter per second (m³/s)

Reference Table

Unit Name	Symbol	Equivalent in 1 m³/s	Quick Pair Page
Cubic meter per second	m³/s	1 m³/s = 1 m³/s	Base Unit
Cubic meter per hour	m³/h	1 m³/s = 3,600 m³/h	m³/s to m³/h →
Liter per second	L/s	1 m³/s = 1,000 L/s	m³/s to L/s →
Liter per minute	L/min	1 m³/s = 60,000 L/min	m³/s to L/min →
Cubic feet per minute (CFM)	CFM	1 m³/s = 2,118.880003 CFM	m³/s to CFM →
Gallon per minute (US GPM)	GPM (US)	1 m³/s = 15,850.323141 GPM (US)	m³/s to GPM (US) →

Hydraulic Pumping & HVAC Airflow Benchmark Reference Chart

Engineering volumetric flow lookup table comparing plumbing fixtures, industrial centrifugal pumps, and ventilation air blowers

Lookup Matrix

System / Flow Application	L/min	US GPM	CFM (ft³/min)	m³/h (Metric)
Water-Saving Bathroom Faucet Aerator	5.7 L/min	1.50 GPM	0.20 CFM	0.34 m³/h
Standard Residential Shower Head	9.5 L/min	2.50 GPM	0.33 CFM	0.57 m³/h
Residential Garden Hose (5/8 inch)	37.8 L/min	10.00 GPM	1.34 CFM	2.27 m³/h
Residential Bathroom Exhaust Fan	2,265 L/min	598.4 GPM	80.0 CFM	135.9 m³/h
Residential Sump Pump (1/3 HP)	151.4 L/min	40.00 GPM	5.35 CFM	9.08 m³/h
Swimming Pool Filter Circulation Pump	302.8 L/min	80.00 GPM	10.69 CFM	18.17 m³/h
Residential Central AC Blower (3 Ton)	33,980 L/min	8,976 GPM	1,200.0 CFM	2,038.8 m³/h
Standard Municipal Fire Hydrant	3,785 L/min	1,000.00 GPM	133.7 CFM	227.1 m³/h
Commercial HVAC Air Handling Unit (AHU)	283,168 L/min	74,805 GPM	10,000.0 CFM	16,990.1 m³/h
Municipal Flood Drainage Pumping Station	189,270 L/min	50,000.00 GPM	6,684.0 CFM	11,356.2 m³/h

Hydraulics & HVAC Engineering

Volume Flow Rate: Fluid Dynamics, Continuity & Pump Sizing Calculations

Comprehensive guide to volumetric throughput, Reynolds numbers, Bernoulli pressure gradients, and unit conversions across plumbing and HVAC ducts.

Fundamental Volumetric Throughput Equation

Volumetric flow rate Q measures the volume of fluid passing through a cross-sectional area per unit of time:

Q = A · v = (π · D² / 4) · v

Conduit Volumetric Flow Formula (Q = m³/s, A = Pipe Area in m², D = Internal Diameter, v = Mean Fluid Velocity)

For incompressible fluids like water, hydraulic oil, and coolants, volumetric flow rate is strictly conserved along a closed piping system regardless of pipe narrowing or expanding: A₁·v₁ = A₂·v₂.

HVAC Airflow (CFM) vs Hydraulic Pumping (GPM)

Engineering sub-disciplines adhere to specific conventional units:

HVAC Ventilation: CFM & m³/h

Air conditioning, exhaust fans, and compressor ratings specify flow in Cubic Feet per Minute (CFM) or m³/h. Standard air cooling rules of thumb designate approximately 400 CFM per 1 ton (12,000 BTU/h) of cooling capacity.

Hydraulics & Plumbing: US GPM & L/min

Centrifugal pumps, water mains, and hydronic heating loops rely on US Gallons per Minute (GPM) or Liters per minute (L/min). Safe piping design guidelines maintain liquid velocities between 4 and 8 ft/s (1.2–2.4 m/s) to prevent erosion and water hammer.

Pressure Drops & Pumping Head Curves

When sizing commercial pumps, the volumetric flow rate Q must be matched to system dynamic head using the Darcy-Weisbach equation for frictional pipe loss:

h_f = f · (L / D) · (v² / 2g)

Darcy-Weisbach Head Loss Formula (h_f = head loss in meters, f = friction factor, L = length, D = diameter)

Because frictional head loss increases quadratically with velocity (h_f ∝ v²), pushing excessive volumetric flow through undersized pipes creates severe pressure drops, excessive pump power consumption, and destructive cavitation.

About Volume Flow Rate Units & Formulas

Multiply the volume flow rate by the factor relative to 1 m³/s.

Cubic meter per secondm³/s

SI unit of fluid volume throughput

Cubic meter per hourm³/h

Industrial pump capacity

Liter per secondL/s

1/1,000 m³/s

Liter per minuteL/min

Common hydraulic flow unit

Cubic feet per minute (CFM)CFM

Air compressor and ventilation throughput

Gallon per minute (US GPM)GPM (US)

Standard plumbing and piping flow unit

FREQUENTLY ASKED QUESTIONS

Volume Flow Rate Converter FAQs

Frequently asked questions regarding volume flow rate conversion metrics, formulas, and real-world calculation standards

How do you convert CFM to GPM?

To convert cubic feet per minute (CFM) to US gallons per minute (GPM), multiply by 7.480519: GPM = CFM × 7.480519.

Physical Principle: Exactly 7.480519 US liquid gallons fit inside one cubic foot of volume (1 ft³ = 7.480519 gal). Thus, an airflow or fluid flow of 100 CFM corresponds to 100 × 7.4805 = 748.05 GPM.

Reverse Conversion: To convert GPM to CFM, divide by 7.480519 (or multiply by 0.133681): 1,000 GPM × 0.133681 = 133.68 CFM.

How do you convert L/min to US GPM?

To convert Liters per minute (L/min) to US gallons per minute (GPM), divide by 3.785412 or multiply by 0.264172: GPM = L/min × 0.264172.

Example: A water filtration system rated at 20 L/min yields 20 × 0.264172 = 5.28 GPM.

Reverse Conversion: Multiply US GPM by 3.785412 to get L/min (e.g., 10 GPM × 3.7854 = 37.85 L/min).

What is volume flow rate in physics and engineering?

Volume flow rate (Q) is the volume of fluid (liquid or gas) which passes through a given cross-sectional area per unit time (Q = V ÷ t).

SI Derived Unit: cubic meters per second (m³/s).
Common Metric Units: Liters per minute (L/min), Liters per second (L/s), cubic meters per hour (m³/h).
Common Imperial Units: Cubic feet per minute (CFM), gallons per minute (GPM).
Cross-Section Velocity Equation: Q = A × v, where A is cross-sectional duct/pipe area (m²) and v is average flow velocity (m/s).

How do you calculate required CFM for HVAC room ventilation?

HVAC engineers size ventilation fans using room volume and Air Changes per Hour (ACH):

CFM = (Room Volume in ft³ × Required ACH) ÷ 60

Example: A 20 ft × 20 ft × 8 ft room has a volume of 3,200 ft³. If code requires 6 air changes per hour: CFM = (3,200 × 6) ÷ 60 = 320 CFM.

What is the relationship between pipe diameter and flow rate at constant pressure?

Under the Hagen-Poiseuille law for laminar viscous pipe flow, flow rate is proportional to the fourth power of the inner pipe radius (Q ∝ r&sup4;). Doubling the pipe diameter increases volumetric flow capacity by 16 times (2&sup4; = 16) for the identical pressure drop across the pipe length.