About

Precise flow rate conversion is critical in industrial plumbing, HVAC balancing, and pump sizing. While the conversion between Liters per minute (L/min) and Cubic meters per hour (m³/h) is a linear scaling, real-world applications often require knowing the resulting flow velocity inside the pipe. High velocities can cause hydraulic shock (water hammer) and erosion, while low velocities may allow sediment buildup. This tool serves engineers and pipefitters by performing the unit conversion and simultaneously calculating the fluid velocity based on the internal pipe diameter. Correctly dimensioning pipework prevents system noise and pressure drops, ensuring pumps operate within their efficiency curves.

Formulas

The volume flow rate conversion is derived from the definitions of the units.

{

1 L/min = 0.06 m³/h1 m³/h = 16.6667 L/min

Velocity (v) is calculated using the flow rate (Q) and the cross-sectional area of the pipe (A), where d is the inner diameter.

v = Qπ ⋅ (d2)²

Reference Data

Flow (L/min)	Flow (m³/h)	Typical Application
10	0.6	Standard Kitchen Faucet
20	1.2	Garden Hose / Shower
50	3.0	Residential Main Line (Small)
100	6.0	Commercial Supply / Small Fire Line
166.67	10.0	Industrial Coolant Pump
250	15.0	Small Irrigation Zone
500	30.0	Commercial HVAC Loop
1000	60.0	Municipal Distribution Branch
1666.67	100.0	Process Water Feed
5000	300.0	Large Scale Dewatering

Frequently Asked Questions

General engineering standards suggest keeping water velocity below 2.5 m/s (approx 8 ft/s) for distribution lines to minimize noise and pipe erosion. For suction lines leading to pumps, the velocity should ideally be below 1.5 m/s to prevent cavitation.

The unit conversion (L/min to m³/h) is valid for any fluid or gas. However, the velocity calculation assumes the fluid is incompressible. For compressed gases, pressure and temperature significantly affect density and velocity profiles.

Flow rate measures volume per time, but velocity measures distance per time. You can have a high flow rate in a large pipe with very slow movement, or the same flow in a tiny pipe moving like a jet. Determining the velocity is essential for safety and efficiency.

Yes. In dosing pumps or chemical injection systems, a difference of 0.001 m³/h can accumulate to a significant volume error over 24 hours. This tool uses 4 decimal places to support precision calibration.