Flow Rate Calculator

Measure Volume Over Time

The flow rate calculator converts measured volume and time into a flow-rate value for pumps, pipes, irrigation, plumbing, HVAC, hydraulic systems, and industrial process systems. Entities include flow meters, rotameters, orifice plates, ultrasonic meters, magnetic meters, SCADA, PLCs, pumps, pipes, valves, and tanks.

This flow rate calculator online supports quick field and desktop checks for water systems, pump tests, HVAC balancing, irrigation zones, and industrial fluid handling.

The flow rate converter helps compare LPM, GPM, CFM, m³/h, L/s, and other common flow units used in metric, SI, and US customary documentation.

To calculate flow rate, divide volume by time. For a pipe, flow can also be calculated from pipe area and velocity using Q = A x v.

This flow rate calculation tool is useful for pump commissioning, bucket tests, pipe-flow estimates, irrigation checks, hydraulic circuits, and process utility systems.

Flow rate can be measured with a bucket test, turbine meter, electromagnetic flow meter, ultrasonic clamp-on meter, differential pressure device, or Coriolis meter. Entities include Endress+Hauser, Siemens, Krohne, Yokogawa, Keyence, and ABB.

For water flow rate, divide liters or gallons by time. Then verify pressure, pipe diameter, valve losses, pump head, and friction loss for engineering use.

Pipe entities include internal diameter, pipe schedule, roughness, Reynolds number, Darcy-Weisbach, Hazen-Williams, friction loss, and pressure drop.

To calculate flow rate from velocity, multiply the pipe or duct area by average velocity. Use consistent units for area and velocity before converting to LPM, GPM, CFM, or m³/h.

Pressure can estimate flow only when geometry or a device coefficient is known. Entities include orifice plates, nozzles, Venturi meters, Cv, Kv, differential pressure, Bernoulli equation, and valve sizing.

Flow rate conversion keeps LPM, GPM, CFM, m³/h, L/s, m³/s, and kg/s values consistent across pump, pipe, HVAC, irrigation, hydraulic, and process documents.

Use it for potable water, process water, cooling loops, booster pumps, filtration, tanks, and municipal water checks.

Use pipe diameter, velocity, pressure drop, roughness, and pipe schedule when moving from quick conversion to design.

Use it beside pump curves, duty points, total dynamic head, NPSH, efficiency, and manufacturer data from Grundfos, Xylem, KSB, Wilo, Ebara, and Goulds.

Use it for sprinkler zones, drip emitters, valves, filters, mainlines, Rain Bird, Hunter, Toro, Netafim, and pump-station checks.

Use it for hydraulic pumps, cylinders, motors, oil flow, control valves, Parker, Eaton, Bosch Rexroth, Danfoss, pressure, and viscosity checks.

LPM is common for metric water, lab, pump, dosing, and commissioning measurements.

GPM is common for US pumps, plumbing fixtures, irrigation equipment, and hydraulic systems.

CFM is common for airflow, HVAC, ventilation, fans, ducts, and air compressors.

m³/h is common for metric pump curves, process plants, water treatment, irrigation mains, and industrial flow.