This flow calculator estimates liters per minute from a timed volume or from full, partially filled, and rectangular channel geometry.
Construction
Liters per Minute Calculator
Calculate liquid flow from a timed volume or from circular and rectangular channel geometry.
Calculator
About this calculator
Formula notes
volume-time: L/min = volume x 60 / seconds; channel flow: Q = cross-sectional area x velocity, with partial-pipe area from the circular segment.
Worked examples
- Example: 10 liters collected in 30 seconds is 20 L/min; a 100 mm full pipe at 2 m/s flows about 942.48 L/min.
- A 0.02 m2 rectangular channel at 3 m/s flows 0.06 m3/s, or 3,600 L/min.
How to use it
- Choose measured volume or a channel mode.
- Enter volume and time, or geometry and flow velocity.
- Read flow in L/min, m3/s, and US GPM.
Frequently asked questions
Which modes are available?
Measured volume and time, full circular pipe, partially filled circular pipe, and rectangular channel.
Do unused geometry fields affect the result?
No. Only the fields required by the selected mode are validated and used.
Limits and interpretation
- The channel models assume uniform velocity and steady flow; friction, roughness, turbulence, and real velocity profiles are not included.
- Partial-pipe area uses a circular segment, and fill depth must stay within the pipe diameter.