Quick example
Convert 1 US gpm to liters per minute
The US liquid gallon is exactly 3.785411784 liters. Because both rates use minutes, one US gallon per minute equals exactly 3.785411784 liters per minute.
From volume and time
How to calculate liters per minute
Flow rate is volume divided by time: Q = V / t. To calculate liters per minute (also spelled litres per minute), divide the liters collected by the elapsed seconds and multiply by 60.
Use a positive measurement time. This is the average over the collection period, not a guarantee of constant flow. If your measurements use other units, start with the volume converter and time converter.
Quick reference
Common volume-flow conversions
| Starting flow | Equivalent |
|---|---|
| 1 L/s | 60 L/min |
| 1 m³/s | 1,000 L/s |
| 1 m³/h | 16.66666667 L/min |
| 1 US gpm | 3.785411784 L/min |
| 1 US gpm | 60 US gph |
| 1 CFM | 28.316846592 L/min |
| 1 CFM | 1.69901079552 m³/h |
| 1 L/min | 0.2641720524 US gpm |
Unit definitions
Metric, gallon, and cubic-foot flow rates
Liters per second and minute
These units express liters passing a point during one second or one minute.
Cubic meters per second and hour
One cubic meter is exactly 1,000 liters; the time base determines the rate.
US gpm and gph
These options use the US liquid gallon of exactly 3.785411784 liters, not the imperial gallon.
CFM
Cubic feet per minute is common for air movement. One cubic foot is exactly 28.316846592 liters.
Volume versus mass
Fluid density is not part of this conversion
These are volumetric flow rates. Turning volume per time into mass per time requires the fluid's density, which can change with temperature, pressure, and composition. This tool does not assume a fluid.
Match the specification
Unit conversion does not change the flow conditions
Converting CFM to L/min does not turn an actual air flow into a standardized air flow. Keep the original pressure and temperature basis when comparing equipment. Likewise, a pressure reading on its own cannot supply the missing flow rate.
The gallon and cubic-foot factors follow the NIST volume conversion tables. The time conversion is applied separately: one minute has 60 seconds and one hour has 60 minutes.
Common questions
Flow-rate conversion FAQ
How many liters per minute are in one US gallon per minute?
One US gallon per minute equals exactly 3.785411784 liters per minute.
How do I convert liters per minute to US gallons per minute?
Divide liters per minute by 3.785411784. For example, 10 L/min is approximately 2.64172 US gpm.
How do I calculate liters per minute from a measured volume?
Divide the collected liters by the elapsed seconds, then multiply by 60. Collecting 10 liters in 30 seconds gives an average flow of 20 L/min. Use a positive elapsed time.
How many liters per minute are in one CFM?
One cubic foot per minute equals exactly 28.316846592 liters per minute. This changes volume units only; it does not correct for air pressure or temperature.
Does gpm mean US or imperial gallons?
Gpm is ambiguous without context. This converter uses US liquid gallons, not imperial gallons. Confirm which gallon the equipment or specification uses before converting.
Can I convert water pressure directly to flow rate?
No. Pressure alone does not determine flow. You also need information about the pipe or opening and the system's resistance. This tool converts an already known volumetric flow rate.