Method: —
Result Summary
| Flow rate | — |
| Per hour | — |
| Liters per minute | — |
| Method | — |
| Comparable to | — |
Typical Fixture Flow Rates
| Fixture | Standard GPM | Low-flow GPM |
|---|---|---|
| Bathroom faucet | 2.2 | 1.0 – 1.5 |
| Kitchen faucet | 2.2 | 1.5 |
| Showerhead | 2.5 | 1.5 – 2.0 |
| Hose bib | 6 – 9 | – |
| Washing machine | 3 – 5 | – |
| Dishwasher | 1 – 2 | – |
| Toilet fill | 2 – 3 | – |
How to Measure Water Flow Rate
Flow rate is the volume of water moving past a point over time, usually expressed in gallons per minute. The simplest and most accurate way to measure it at home is the bucket test: open the fixture all the way, time how many seconds it takes to fill a container of known size, and divide. If you cannot run the water, you can estimate flow from pipe size and an assumed velocity, or from the available water pressure and the length of pipe. The calculator above supports all three methods and converts the result to gallons per minute, gallons per hour, and liters per minute.
Bucket Test Method
Grab a bucket or container with a known volume, such as a five-gallon bucket. Place it under the fully open faucet, hose, or showerhead and start a timer the moment water begins filling it. Stop when it reaches a marked volume and note the seconds. Flow in gallons per minute equals the gallons collected divided by the seconds, times sixty. For example, filling a five-gallon bucket in thirty seconds is ten gallons per minute. Run the test at the fixture you care about, since flow varies across the house.
GPM vs GPH vs LPM
These are all the same measurement expressed over different time spans or units. Gallons per minute is the standard for fixtures and pumps. Gallons per hour, which is simply GPM times sixty, is common for pumps and irrigation. Liters per minute is the metric equivalent, equal to GPM times about 3.785. Knowing all three lets you compare a fixture rated in GPM to a pump rated in GPH or a European fixture rated in LPM.
Frequently Asked Questions
What is a normal home flow rate? Most fixtures run 1.5 to 2.5 GPM; a hose bib can reach 6 to 9 GPM with good pressure.
Why is my flow low? Common causes are a clogged aerator, a partly closed valve, scale buildup, or low household pressure.
Which method is most accurate? The bucket test, because it measures actual delivered water rather than estimating from pressure or pipe size.
How do I convert GPM to LPM? Multiply gallons per minute by 3.785 to get liters per minute.