Volumetric Flow Converter

The volumetric flow rate (Q) is the volume of liquid or gas that passes a point each second: Q = V / t, or the flow speed times the pipe's cross-section, Q = v * A. Its SI unit is the cubic meter per second (m³/s).

In practice, water and pumps are rated in liters per minute or US gallons per minute (GPM), heating and ventilation in m³/h or cubic feet per minute (CFM), rivers in m³/s, and oil in barrels.

How to convert flow units

Type a value into any field, and every other unit is calculated at once. For example, a pump delivering 50 GPM:

1. In L/min: multiply by 3.78541, the liters in a US gallon.

   50 * 3.78541 = 189.3 L/min

2. In m³/h: multiply that by 60 and divide by 1,000.

   189.27 * 60 / 1,000 = 11.36 m³/h

A fan moving 1,000 CFM is 1,699 m³/h.

Common conversions

The gallons and barrels here are US units. A US oil barrel is 42 US gallons, 158.99 L.

Flow units

• Meter³ / second (m³/s): The volume of fluid in cubic meters, passing through a point in one second. This is the base unit of volumetric flow rate.
  Conversion Factor: 1 m³/s = 3600 m³/h

• Meter³ / minute (m³/min): The volume of fluid in cubic meters, passing through a point in one minute.
  Conversion Factor: 1 m³/min = 1 m³ / 60 s = 0.0166667 m³/s

• Meter³ / hour (m³/h): The volume of fluid in cubic meters, passing through a point in one hour.
  Conversion Factor: 1 m³/h = 1 m³ / 3,600 s = 0.00027778 m³/s

• Centimeter³ / minute (cm³/min): The volume of fluid in cubic centimeters, passing through a point in one minute.
  Conversion Factor: 1 cm³/min = 0.000001 m³ / 60 s = 0.0000000166667 m³/s

• Centimeter³ / second (cm³/s): The volume of fluid in cubic centimeters, passing through a point in one second.
  Conversion Factor: 1 cm³/s = 0.000001 m³ / 1 s = 0.000001 m³/s

• Liter / minute (l/min): The volume of fluid in liters, passing through a point in one minute.
  Conversion Factor: 1 l/min = 0.001 m³ / 60 s = 0.0000166667 m³/s

• Liter / second (l/s): The volume of fluid in liters, passing through a point in one second.
  Conversion Factor: 1 l/s = 0.001 m³ / 1 s = 0.001 m³/s

• Milliliter / minute (ml/min): The volume of fluid in milliliters, passing through a point in one minute.
  Conversion Factor: 1 ml/min = 0.001 l/min = 0.0000000166667 m³/s

• Milliliter / second (ml/s): The volume of fluid in milliliters, passing through a point in one second.
  Conversion Factor: 1 ml/s = 0.001 l/s = 0.000001 m³/s

• US Gallon / minute (gal/min): The volume of fluid in U.S. gallons, passing through a point in one minute.
  Conversion Factor: 1 gal/min = 0.00006309 m³/s

• US Gallon / second (gal/s): The volume of fluid in U.S. gallons, passing through a point in one second.
  Conversion Factor: 1 gal/s = 0.00378541 m³/s

• US Barrel / minute (bbl/min): The volume of fluid in U.S. barrels, passing through a point in one minute.
  Conversion Factor: 1 bbl/min = 0.0026498 m³/s

• US Barrel / second (bbl/s): The volume of fluid in U.S. barrels, passing through a point in one second.
  Conversion Factor: 1 bbl/s = 0.1589873 m³/s

• Yard³ / minute (yd³/min): The volume of fluid in cubic yards, passing through a point in one minute.
  Conversion Factor: 1 yd³/min = 0.012742581 m³/s

• Yard³ / second (yd³/s): The volume of fluid in cubic yards, passing through a point in one second.
  Conversion Factor: 1 yd³/s = 0.764554858 m³/s

• Foot³ / minute (ft³/min): The volume of fluid in cubic feet, passing through a point in one minute.
  Conversion Factor: 1 ft³/min = 0.000471947 m³/s

• Foot³ / second (ft³/s): The volume of fluid in cubic feet, passing through a point in one second.
  Conversion Factor: 1 ft³/s = 0.0283168 m³/s

• Inch³ / minute (in³/min): The volume of fluid in cubic inches, passing through a point in one minute.
  Conversion Factor: 1 in³/min = 0.000000273118 m³/s

• Inch³ / second (in³/s): The volume of fluid in cubic inches, passing through a point in one second.
  Conversion Factor: 1 in³/s = 0.000016387064 m³/s

Frequently asked questions

How do I get a flow rate from a bucket and a stopwatch?

Divide the volume by the time. A 10 L bucket that fills in 25 seconds means 10 / 25 = 0.4 L/s, or 24 L/min.

How do I convert a volume flow to a mass flow?

Multiply by the density: ṁ = ρ * Q. 2 L/s of water (1 kg/L) is 2 kg/s. Mass flows are converted in the Mass Flow Converter.