How to Replace Bathroom Sink Faucet Aerator? | DIY In 5 Minutes

Replacing a bathroom sink faucet aerator takes about five minutes: unscrew the old one, match the thread size and type, then install the new unit and check for leaks.

That slow trickle from your bathroom faucet usually means the aerator — the small mesh screen inside the spout tip — is clogged with mineral deposits. The fix is simple and costs a few dollars, and knowing how to replace bathroom sink faucet aerator parts correctly avoids leaks and stripped threads. Before you buy, you need to know which thread type your faucet uses, then the swap itself takes minutes.

What You Need To Know Before Buying A Replacement

Bathroom faucet aerators come in a few standard thread sizes and two thread types, and choosing the wrong one is the most common mistake. Aerators use either male threads, which screw into the faucet spout, or female threads, which screw onto a threaded spout. NEOPERL’s guide says the correct replacement depends on both the male or female thread type and the aerator size.

Standard residential sizes in the US include:

• M24x1 (STD) — the most common standard size
• M21.5×1 (JR) — a smaller, common size
• M18.5×1 (TJ) — used on many newer faucets
• M16.5×1 (TT) — a compact size

NEOPERL also makes Caché Shorty aerators in M16x1 and M18x1, which are fully compatible with the common Caché sizes. If you are unsure which size your faucet needs, unscrew the old aerator first and match it against the packaging in the hardware store.

How To Remove The Old Aerator

Start by covering the sink drain — a dropped aerator part disappears down a drain fast. The Spruce recommends laying a towel in the sink to catch any pieces that fall. Then, most aerators unscrew by hand: turn the collar counterclockwise. If it is stuck, a damp washcloth wrapped around the collar gives you the grip to twist it off, and NEOPERL recommends using a service key for stubborn units.

Here is the one step people miss: the small rubber washer often sticks inside the faucet spout when you remove the aerator. NEOPERL specifically warns that this washer frequently stays behind, so check inside the spout and pull it out before installing the new aerator. If mineral buildup is heavy, you may need a service wrench rather than just your fingers.

Installing The New Aerator

Once the old unit is off, place the new gasket — the rubber ring — into the aerator or onto the spout, depending on your thread type. The Spruce says the aerator will not work without its gasket, and you should use the new one that comes with the replacement. Reusing the old gasket risks leaks and failure.

Screw the new aerator on by hand, turning clockwise, and tighten it until it is snug. Avoid over-tightening: NEOPERL recommends a firm hand tightening, not excessive force, which can strip the threads or crack the housing. If you are using a service key, stop once the aerator seats firmly.

Turn the water back on and check for drips. If you see water seeping between the faucet and the aerator, NEOPERL says to reinstall the aerator or tighten it more firmly with the key.

If you are upgrading rather than replacing, the best-rated bathroom sink faucet aerators are worth a look before you buy.

Choosing The Right Flow Rate

Aerators also control water flow, which is measured in gallons per minute (gpm) or liters per minute (l/min). Standard bathroom aerators range from 1.0 to 2.2 gpm, with lower-flow options saving water without sacrificing pressure.

For a bathroom sink, a 1.5 gpm aerator works well for daily handwashing, while a 2.2 gpm unit feels stronger if you prefer more pressure. Flow rate does not affect the thread size, so any aerator that fits your spout will work regardless of its gpm rating. Match the size first, then pick your preferred flow.

NEOPERL’s official aerator replacement guide covers the full process, including how to use a service key without scratching chrome finishes. If your aerator is corroded or seized, a service key is the safest tool to remove it without damaging the faucet’s finish.