A faucet aerator is the small screen at the tip of your faucet. Swapping an old one for a low-flow model takes about five minutes, usually needs no tools and can save hundreds of gallons of water a year. It is one of the cheapest water-saving upgrades you can make.
Quick answer: Unscrew the old aerator by hand (counterclockwise), take it to the store to match the size and thread, buy a WaterSense labeled replacement and screw it on hand-tight. Turn on the water and check for drips around the threads.
Why install a faucet aerator
Faucets use more water than you might think. Standard faucets flow at about 2.2 gallons per minute, while WaterSense labeled bathroom faucets and aerators use no more than 1.5 gallons per minute, cutting flow by 30 percent or more. EPA estimates the average family can save about 700 gallons of water a year by installing WaterSense faucets or aerators, about the amount used in 45 showers (EPA WaterSense).
Less hot water flowing down the drain also means less energy used by your water heater. Aerators often cost just a few dollars, and they mix air into the stream so it still feels strong. That makes them a smart fit for drought-prone places like California.
What you need
- A replacement aerator with the WaterSense label (bring the old one to match size)
- A rag or towel
- Pliers or an adjustable wrench, only if the aerator is stuck
- Plumber’s tape (optional)
- White vinegar and an old toothbrush (optional, for cleaning threads)
- An aerator key, if your faucet has a hidden (recessed) aerator
How to install a faucet aerator
- Close the drain. Put in the sink stopper or lay a towel in the sink so small parts can’t fall down the drain.
- Remove the old aerator. Grip it and turn it counterclockwise (looking down from above). If it won’t budge, wrap it in a rag and gently use pliers. Recessed aerators need a matching plastic aerator key.
- Check the size. Note whether the threads are on the outside (male) or inside (female) and whether it is a regular, junior or tom thumb size. The easiest way is to bring the old aerator to the store.
- Clean the faucet threads. Scrub away mineral buildup with an old toothbrush and a little vinegar.
- Choose a WaterSense model. Look for the WaterSense label or a flow rate of 1.5 gallons per minute or less for bathroom sinks. Kitchen sinks often use a slightly higher flow so pots fill faster.
- Install the new aerator. Make sure the rubber washer is seated inside. Screw it on clockwise by hand until snug. Wrap threads with plumber’s tape first if needed.
- Test it. Turn on the water and look for leaks around the threads. If it drips, tighten about a quarter turn. Avoid overtightening with pliers, which can crack the part.
Tips
- Do every faucet. Bathrooms are the easiest wins. Swap them all at once.
- Clean aerators once or twice a year. Soak them in vinegar to remove mineral buildup that slows flow.
- Check for rebates or freebies. Many water utilities, including some in California, offer free or discounted aerators.
- Pair with other upgrades, like a low-flow showerhead, for even bigger savings.
Frequently asked questions
How much water does a faucet aerator save?
A WaterSense aerator limits a bathroom faucet to 1.5 gallons per minute or less, which cuts flow by 30 percent or more compared to a standard 2.2 gpm faucet. EPA estimates a typical family can save about 700 gallons a year.
How do I know what size aerator I need?
Check whether the threads on your faucet are inside or outside, and match the size. The simplest method is to bring your old aerator to a hardware store and compare it to the new ones.
Will a low-flow aerator lower my water pressure?
It lowers the amount of water, not the feel. Aerators mix air into the stream, so the water still feels strong for washing hands.
How do I remove a recessed faucet aerator?
Recessed or hidden aerators sit inside the faucet tip and need a small plastic aerator key. Many new aerators come with one, or you can buy one at a hardware store.
See your water impact
Want to see how faucets, showers and outdoor watering add up in your home? Try our free Household Water Simulator to estimate your water use and find the changes that save the most.
Related guides
- How to Use a Shower Timer to Build a Shorter-Shower Habit
- How to Convert an Old Toilet to Dual-Flush
- How to Install a Smart Leak Detector That Texts You for Free
Sources
- U.S. EPA WaterSense, Bathroom Faucets
Written and reviewed by the Accessible Sustainability Alliance editorial team. Last updated October 5, 2026.
