Estimate pump flow rate in GPM, GPH, LPM, and CFS from pump horsepower, total dynamic head, efficiency, pipe size, tank fill time, or known pump capacity. Use this for water pumps, booster pumps, transfer pumps, well pumps, irrigation pumps, and general plumbing flow planning.
Flow from horsepower:
The calculator estimates flow from pump horsepower, total dynamic head, and efficiency.
Flow from tank fill time:
The calculator divides tank volume by fill time to estimate pump flow rate.
Flow from pipe velocity:
The calculator uses pipe area and water velocity to estimate flow.
Capacity check:
The calculator compares known pump flow against required flow and shows the margin.
A pump flow rate calculator helps estimate how much water a pump can move through a system.
It can help compare GPM, GPH, LPM, total dynamic head, horsepower, efficiency, pipe velocity, required flow, and capacity margin.
Your result shows estimated pump flow rate and related values. Use this as a planning estimate only. Actual pump flow depends on the pump curve, impeller design, motor speed, suction conditions, total dynamic head, pipe size, fittings, valves, and system layout.
Pump flow rate is the amount of water a pump moves over time. It is commonly shown in gallons per minute, gallons per hour, or liters per minute.
You can estimate GPM from pump horsepower and head, from tank volume and fill time, or from pipe area and water velocity.
Higher head means the pump must push against more resistance. As head increases, the actual pump flow usually decreases.
No. This calculator gives a planning estimate. Final pump flow should be checked against the manufacturer pump curve for the actual total dynamic head.