Flow Rate Calculator
Measure a known volume of water and how many seconds it takes to fill. The calculator converts the result to gallons per minute and liters per minute.
Please enter a measured volume and fill time greater than zero.
ESTIMATED FLOW RATE—
Gallons per minute—
Liters per minute—
Measured time—
Repeat the test two or three times and average the results if you need a more stable estimate.
What does GPM mean?
GPM means gallons per minute. It is a flow-rate measurement commonly used to describe how much water moves through a faucet, shower, hose or other outlet over time.
Why can flow rate change?
Aerators, valves, clogged screens, pipe restrictions, pressure, fixture design and simultaneous water use elsewhere in the building can all affect the measured flow.