Water Flow Converter
Convert water flow between GPM, LPM, cubic meters per hour, and cubic feet per second.
Type in any field and the others update automatically.
Type in any field — the others update instantly.
Water flow rate conversion factors.
Base conversions:
- 1 GPM (US gallon/min) = 3.7854 LPM (liters/min)
- 1 GPM = 0.2271 m3/h (cubic meters/hour)
- 1 GPM = 0.002228 ft3/s (cubic feet/second)
- 1 LPM = 0.2642 GPM
- 1 m3/h = 4.4029 GPM = 16.667 LPM
Common flow rates:
- Shower head: 2.0-2.5 GPM (7.6-9.5 LPM)
- Kitchen faucet: 1.5-2.2 GPM (5.7-8.3 LPM)
- Garden hose: 5-10 GPM (19-38 LPM)
- Fire hydrant: 500-1,500 GPM (1,893-5,678 LPM)
- Swimming pool pump: 40-80 GPM (151-303 LPM)
US vs Imperial gallons:
- 1 US gallon = 3.785 liters
- 1 Imperial gallon = 4.546 liters
- This converter uses US gallons.
Water flow rate is what decides whether a shower feels strong or a pump can keep up with demand. It’s worth separating from water pressure, which people often blame by mistake. Pressure is the push (psi or bar); flow is how much actually comes out per minute. A narrow or partly clogged pipe can show high pressure yet deliver poor flow, so a weak shower isn’t always a pressure problem, and a flow restrictor in the showerhead is often the real culprit.
Flow also isn’t constant through a system. Every fitting, bend, and length of pipe adds resistance that saps flow by the time water reaches the tap, which is why the rate at a far bathroom runs lower than at the one nearest the main. When sizing a pump or judging a fixture, the flow that matters is the one measured at the point of use, not the headline number on the box.
How we build and check this converter
This converter runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
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