What You Need to Check Water Pressure

You can measure your home's water pressure with a pressure gauge, a straightforward tool that screws onto an outdoor faucet or hose bib. The gauge reads pressure in pounds per square inch (PSI) and costs between $10 and $30 at hardware stores. Most homes run between 40 and 80 PSI; anything below 40 suggests a problem, and anything above 80 can damage pipes and appliances.

You do not need a plumber to take this measurement yourself. The process takes five minutes and requires no special knowledge. If your reading falls outside the normal range, you then know whether to call a professional and what to tell them.

Key Takeaways

  • A water pressure gauge screws onto an outdoor faucet and shows your PSI reading in seconds, with normal household pressure between 40 and 80 PSI.
  • Turn off major water users (washing machine, dishwasher, showers) before testing so the reading reflects your actual supply pressure, not demand pressure.
  • Low pressure below 40 PSI often points to a clogged inlet valve, mineral buildup in pipes, or a problem at the meter, while high pressure above 80 PSI usually means you need a pressure regulator.
  • Test at multiple faucets around your house to tell whether low pressure is a whole-house problem or isolated to one area.

Where to Attach the Gauge

Find an outdoor faucet or hose bib—the threaded spout where you connect a garden hose. These are usually on the side or back of your house, closest to where the water line enters. If you have more than one outdoor faucet, use the one nearest to the street or meter, since that reading reflects your incoming pressure before it splits to different parts of the house.

Turn off the hose if one is attached. Screw the gauge clockwise onto the faucet threads until it is snug. Do not force it; hand-tight is enough. The gauge needle or digital display will show your PSI within a few seconds.

How to Get an Accurate Reading

Before you measure, turn off water-using appliances. Stop any showers, turn off the washing machine and dishwasher, and wait a minute for the pipes to settle. This matters because the gauge reads pressure, not flow—if someone is running water elsewhere, the pressure drops and your reading will be artificially low.

Take the reading with the outdoor faucet turned off. You are measuring the pressure in the supply line, not the pressure coming out of the faucet. Write down the number. If you want to be thorough, test again at an indoor faucet by attaching the gauge to the aerator (the screen at the tip) after unscrewing it, though the outdoor reading is usually more reliable.

What Low Pressure Means

If your gauge reads below 40 PSI, water moves slowly through your pipes and appliances struggle to work properly. Showers feel weak, dishwashers run longer cycles, and washing machines may not fill completely. The cause is usually one of three things: a clogged inlet valve where the water line enters your house, mineral buildup inside older pipes, or a problem at the meter or with the water company's supply.

Check your main water shut-off valve (usually near the meter or where the line enters the house) to see if it is partially closed. If it is fully open and pressure is still low, the blockage is likely inside the valve itself or further down the line. Mineral buildup in galvanized steel pipes is common in older homes and requires a plumber to flush or replace sections of pipe.

What High Pressure Means

Pressure above 80 PSI is too much. It stresses pipes, causes leaks at joints, shortens the life of water heaters and appliances, and can trigger a banging sound in the walls when you turn off a faucet suddenly. High pressure usually comes from the water company's supply line, especially in areas fed by gravity from a water tower or reservoir at high elevation.

The fix is a pressure regulator, a valve that screws onto the main water line where it enters your house and reduces incoming pressure to a safe level. Regulators cost $50 to $150 and take a plumber about an hour to install. If you already have a regulator and pressure is still high, the regulator may be failing and needs replacement.

Testing Different Areas of Your House

If you found low pressure at the outdoor faucet, test an indoor faucet in the kitchen and a bathroom to see whether the problem is everywhere or just in one area. Low pressure at the outdoor faucet but normal pressure indoors suggests the outdoor line has a leak or blockage. Low pressure everywhere points to a supply problem or a clogged inlet valve.

If one bathroom has low pressure but others do not, the problem is likely in that branch of pipe—a mineral clog or a partially closed shut-off valve under the sink. Knowing where the pressure drops helps a plumber pinpoint the issue faster and saves you money on diagnosis.

When to Call a Plumber

Call a plumber if your pressure stays below 40 PSI after you have confirmed the main shut-off valve is fully open, or if pressure is above 80 PSI and you do not have a regulator. You should also call if pressure is normal at the meter but low inside the house, since that points to a blockage or leak in your home's pipes rather than a supply issue.

Bring your gauge reading with you or have it ready when you call. It tells the plumber whether the problem is incoming supply (their job or the water company's) or inside your home (definitely their job). A pressure reading also helps them decide whether to flush the pipes, replace a valve, or install a regulator.

Frequently Asked Questions

Can I use a tire pressure gauge to check water pressure?

No. Tire gauges measure PSI but are not designed for water and will not fit most faucets. Buy a water pressure gauge made for the job—they are inexpensive and thread onto standard faucets. Look for one labeled "water pressure gauge" at any hardware store.

What if my pressure changes throughout the day?

Pressure often drops during peak hours (morning and evening) when many people are using water at once. Test in the early morning before anyone showers or uses water to get your baseline supply pressure. If it is still low, the problem is not demand—it is a supply or blockage issue.

Do I need to turn off the water before attaching the gauge?

No. The gauge screws on while water is in the line. You do not need to shut off anything. Just turn off the faucet itself so water does not run while you are reading the gauge.

Is 60 PSI good water pressure?

Yes. Sixty PSI is in the middle of the normal range and is what most homes aim for. It is strong enough for showers and appliances but not so high that it stresses pipes. Anything between 50 and 70 PSI is ideal.

What does it mean if pressure is normal but water still comes out slowly?

Normal pressure with slow flow usually means a clogged aerator (the screen on the faucet tip) or a problem specific to that faucet, not a whole-house issue. Unscrew the aerator, rinse it, and screw it back on. If flow improves, mineral buildup was the culprit. If it does not, the faucet valve itself may be failing.