Flow Rate Converter

Convert a volumetric flow rate between common metric and US customary units

Your result will appear here.

About the Flow Rate Converter

Flow Rate Converter changes volumetric flow between units such as litres per minute, gallons per minute, cubic metres per hour and cubic feet per second. It is useful for pumps, plumbing, irrigation and process systems where capacity is quoted in different units.

A flow rate combines volume and time, so both parts of the unit must be converted. Changing only the volume unit or only the time unit will produce the wrong result.

How to Use the Flow Rate Converter

  1. Enter the known flow rate.
  2. Identify its current volume-per-time unit.
  3. Select the target flow-rate unit.
  4. Convert and keep the same physical flow basis, such as U.S. gallons versus Imperial gallons.

How the Calculation Works

The converter maps the source rate to a common volume-per-time basis and then applies the target volume and time factors.

For example, converting litres per minute to litres per second divides by 60, while converting U.S. gallons to litres also multiplies by the appropriate gallon conversion factor.

Worked example

Flow Rate Converter Worked Example

120 L/min to L/s

120÷60 = 2 L/s.

Result guide

Understanding Your Flow Rate Converter Result

The result represents the same volumetric flow expressed in another unit. It does not account for pressure losses, pipe diameter or pump performance.

Before you rely on the answer

Assumptions and Limitations

  • Source and target units are volumetric flow units.
  • U.S. and Imperial gallon conventions are identified correctly.
  • Flow is treated as a steady average rate.

Practical tip

Using This Result in Practice

For pump and irrigation work, convert the rated flow first, then check whether the system can actually deliver that rate at the required pressure or head. Unit conversion alone does not validate pump sizing.

Related calculations

Useful Calculations to Continue With

If you know tank volume and converted flow and want fill duration, use the Water Tank Fill Time Calculator.

If airflow rate and duct area are known and you need air velocity, use the Duct Velocity Calculator.

Authoritative references

Useful Official Sources

For standards, definitions or real-world guidance related to this calculation, these primary sources may be useful:

Common questions

Flow Rate Converter FAQ

How do I convert litres per minute to litres per second?

Divide by 60.

Are U.S. and Imperial gallons per minute equal?

No. The gallon definitions differ.

Does converting flow rate account for pressure?

No. It changes units only.