Everything you need to know about your faucet’s water flow rate

What is a flow rate?

Understanding your faucet's flow rate is crucial. It affects water bills, home efficiency, and satisfaction with water pressure. Whether it's a low flow faucet or a higher flow faucet, knowing your flow rate is key.

Flow rate is how fast water flows, but it's more. Water treatment systems, like heaters and softeners, need time for chemical reactions. If systems are too small, you may run out of hot or clean water quickly. Understanding and maintaining your flow rate is crucial to avoid shortages.

The Environmental Protection Agency (EPA) estimates that showers consume about 1.2 trillion gallons of water very year in the United States – kitchen and bathroom faucets account for 19% of the average home’s water usage. To keep you bills low and your home environmentally friendly, take a closer look at your faucets’ and shower heads’ flow rates to learn how you can conserve and save.

Terms you should know

• GPM: gallons per minute – units in which water flow rate is measured
• PSI: pounds per square inch – units in which water pressure is measured
• Aerator: a small, round device screwed to the tip of the spout that restricts the faucet’s water flow rate

Why flow rate is important

Water flow rate is crucial but often overlooked. If it's not just a trickle but not explosive, it might seem fine, but that's not always true. Running out of hot water quickly could signal an inappropriate flow rate.

Incorrect flow rates with a water softener can lead to running out of clean water. For homes with water wells, flow rate is vital. Ensure your water pipes are efficient for optimal functionality.

How much water per minute does a faucet use?

The average flow rate for faucets is between 1.0 gpm and 2.2 gpm. In the US, the maximum flow rate for kitchen and bathroom faucets is 2.2 gpm at 60 psi. In more environmentally regulated areas, the maximum flow rates are further restricted. For example, Georgia is down to 2.0 gpm and California is at 1.8 gpm.

Many bathroom faucets have a much lower water flow rate than kitchen faucets. Bathroom faucets can run at 0.8 gpm – 1.5 gpm without a noticeable reduction in what most of us refer to as “water pressure”.

How can you measure water pressure and flow rate?

If you suspect that your water pressure if either too high or too low, there’s a simple way for you test it. The most accurate method is to buy a pressure gauge from your local hardware store and hook up to a hose. Check the measurement on the pressure gauge when all other faucets and water-using fixtures are turned off to get a baseline reading. In general, you want the household plumbing to provide between 40 - 60 psi.

If you’d rather not spend additional expenses on a pressure gauge, there’s a much simpler way to check for low water pressure. For example, let’s say you’re considering purchasing a home and want to measure the water pressure but you didn’t bring a pressure gauge along for the tour. Try this instead: turn on the shower and sink faucets in a bathroom, flush the toilet, and observe the water flow in the shower. If it appears to drop significantly when the toilet is flushing, you should investigate further before signing off on the home.

To measure the flow rate of your faucet, you’ll need a container large enough to hold a gallon of water, a measuring cup, and a stopwatch or timer or some kind:

1. Place the container under the faucet’s spout.
2. Open the handle on the faucet and, at the same time, start the time on your stopwatch. It’s important that these two actions be done at the exact same time.
   • Note: If you’re measuring for the maximum flow rate, make sure that the handle is fully open. If you have a two-handle faucet, make sure that both are fully open.
3. Once the container is full, divide 60 by the number of seconds it took to fill (i.e.; if it took 30 seconds to fill then 60/30 = 2 gallons per minute).

What can affect water flow rate?

A faucet’s water flow rate can be affected by a variety of factors. Since the EPA limits water flow at 2.2 gpm, most modern faucets now come with a pre-installed aerator that limits the flow to 2.2 gpm while also infusing the water stream with air to reduce splashing.

The diameter of your pipes can also play a large role in regulating your water flow – wider pipes allow more water to pass, resulting in a higher flow rate.

One reason water flow may be reduced is it you have a build-up of mineral deposits inside your faucet. It’s very common for aerators to become partially blocked depending on the length of time it’s been in use, which can limit the amount of water that can pass through.

Other factors may include where you live – for several reasons, some areas simply have lower water pressure, which will reduce the water flow rate.

Water pressure can also vary according to demand. It’s very common for flow rate to be weaker in the morning when all your neighbors are taking their showers before heading off to school or work.

How can you reduce a faucet’s flow rate?

Most faucets have a small, round device screwed to the tip of the spout. This is the aerator. It’s the aerators job to create a mixture of water and air, which helps to make the water stream smoother in addition to limiting the water flow to an acceptable level.

If your water flow is too high and you want to reduce it to help save some money, you can install a new aerator that further restricts the water flow.

Consider replacing the aerator if your water flow is too high, particularly if you're aiming to cut costs and don't require excessive water, especially with kitchen faucet low pressure.

How can you increase your faucet’s flow rate?

If you're wondering how to increase water pressure in the kitchen sink or bathroom, these steps can help improve flow. In most cases, the easiest way to increase a faucet’s flow rate is by replacing the aerator. Try looking for a higher gpm model to allow for more gallons per minute. If you live in a low water pressure area, an aerator designed to restrict water flow might be reducing the flow too much.

However, before you rush out to buy a new aerator, you should also check to see if the old one is blocked. If you remove it from the faucet and look inside, you may see that it’s filled with mineral deposits. Areas with hard water see this type of blockage pretty frequently.

To clean it, you can try boiling it in vinegar for about 30 minutes – this will help dissolve and dislodge the minerals from the aerator screen.

Alternatively, you can try a more tedious method to clear out the blockage. Use a small pin to push through each individual hole in the aerator – this will allow the water to pass through freely.

If cleaning the aerator doesn’t help, you should also check for leaks in your plumbing. If you’re losing water in this way, it will reduce the water flow in your faucet, as well.