Flow Rate converter

Flow rate, or volumetric flow rate, measures the volume of fluid passing a point per unit of time. The SI unit is the cubic meter per second (m³/s). Liters per minute and cubic meters per hour are common for pumps, water supply, and process equipment.

Convert between 12 flow rate units. Pick any two units below; results update as you type.

From

Popular flow rate conversions

About flow rate units

In the US, airflow for fans and HVAC systems is rated in cubic feet per minute (CFM), and water flow in gallons per minute (GPM). The US gallon is smaller than the imperial gallon, so a pump rated in US GPM delivers less than the same number in UK gallons per minute. River and stream flows are often given in cubic feet or cubic meters per second.

Volumetric flow differs from mass flow, which is measured in units such as kilograms per second. For gases, volumetric flow depends on temperature and pressure, so values are often quoted at standard conditions.

Tips

Confirm whether a GPM rating uses US or imperial gallons; the imperial gallon is about 20% larger.
One liter per second equals exactly 3.6 cubic meters per hour, since an hour has 3,600 seconds.
For gas flow, check whether the figure is at actual or standard conditions before comparing equipment.

All flow rate units

Unit	Symbol	Value in liters per second
Liters per Second	L/s	1 L/s = 1 L/s
Cubic Meters per Second	m³/s	1 m³/s = 1,000 L/s
Cubic Feet per Second	ft³/s	1 ft³/s = 28.31685 L/s
Liters per Minute	L/min	1 L/min = 0.01666667 L/s
Cubic Meters per Minute	m³/min	1 m³/min = 16.66667 L/s
Cubic Feet per Minute	CFM	1 CFM = 0.4719474 L/s
Liters per Hour	L/h	1 L/h = 0.0002777778 L/s
Cubic Meters per Hour	m³/h	1 m³/h = 0.2777778 L/s
Cubic Feet per Hour	ft³/h	1 ft³/h = 0.007865791 L/s
Cubic Meters per Day	m³/d	1 m³/d = 0.01157407 L/s
Imperial Gallons per Minute	gpm (UK)	1 gpm (UK) = 0.07576817 L/s
US Gallons per Minute	gpm	1 gpm = 0.0630902 L/s

Factors: NIST SP 811 · SI Brochure · NIST Handbook 44 — Updated October 17, 2026