What You Need and Where to Start
You can measure your home water pressure in about five minutes with a tool called a water pressure gauge, which costs $10 to $20 at any hardware store. The gauge screws onto an outdoor faucet or a hose bib — the same connection where you attach a garden hose. You do not need a plumber or special training; you just need to know which faucet to use and how to read the dial.
The best place to test is an outdoor faucet on the side of your house closest to where the water line enters. If you do not have an outdoor faucet, you can test at a laundry room or basement sink, but outdoor faucets give the most accurate reading because they are closest to the main water supply. Avoid testing at a faucet that is far from the entry point, because pressure drops as water travels through pipes.
Key Takeaways
- A water pressure gauge screws onto any outdoor faucet and shows your pressure in pounds per square inch (PSI) within seconds.
- Normal household water pressure ranges from 40 to 80 PSI; readings below 40 or above 80 signal a problem worth investigating.
- Test at an outdoor faucet on the side of your house closest to the water meter for the most accurate reading.
- Turn off all other water use in the house before testing so that running appliances do not lower the pressure reading.
How to Attach and Read the Gauge
Turn off all water use in your home first — no showers, no washing machines, no toilets running. This ensures you are measuring the pressure when nothing else is drawing water. Wait a minute or two for the system to settle.
Locate the outdoor faucet and turn the handle all the way off. Unscrew the aerator (the small screen at the tip of the faucet) by turning it counterclockwise by hand. Screw the water pressure gauge onto the faucet in its place, turning clockwise until it is snug. Do not force it; hand-tight is enough.
Turn the faucet handle on slowly and fully. The gauge needle will jump to a number and hold steady within a few seconds. Read the number where the needle points — that is your water pressure in PSI. Turn the faucet off, unscrew the gauge, and screw the aerator back on.
What Your Reading Means
Water pressure between 40 and 80 PSI is normal for most homes. Pressure below 40 PSI means water flows slowly from your faucets and showers, and appliances like dishwashers may not work well. Pressure above 80 PSI can damage pipes, fixtures, and water heaters over time and may cause banging sounds when you turn off a faucet.
If your reading is below 40 PSI, the problem could be a partially closed shut-off valve, a clogged water line, or low pressure from your water company. If your reading is above 80 PSI, you may need a pressure regulator installed where the water line enters your house. A plumber can diagnose and fix either problem, but knowing your pressure reading before you call saves time and money.
Testing at Different Times of Day
Water pressure changes throughout the day because demand on the water system rises and falls. Morning and evening, when many people shower and run appliances, pressure often drops. Midday and late night, when fewer people are using water, pressure rises. If you are concerned about low pressure, test at different times — morning, afternoon, and evening — to see if the problem is constant or only at peak hours.
If pressure is normal in the afternoon but drops to 30 PSI in the morning, the issue is likely demand on the municipal system, not your home. If pressure is consistently low all day, the problem is in your house or the line from the street to your meter.
Common Mistakes That Skew Your Reading
The most common mistake is testing while other water is running. A washing machine, dishwasher, or shower in another part of the house will lower the pressure you measure. Always turn off all water use and wait a minute before testing.
Another mistake is testing at an indoor faucet far from the main line, such as a second-floor bathroom. Pressure naturally drops as water travels upward and through long pipes. If you must test indoors, test at the lowest point in the house — a basement or laundry room sink — and know that the reading will be slightly lower than at the outdoor faucet.
Do not force the gauge onto the faucet or turn it on suddenly. A gentle hand-tight fit and a slow opening of the faucet handle prevent damage to the gauge and give you a stable reading.
When to Call a Plumber
If your reading is below 40 PSI and stays low all day, or if it is above 80 PSI, contact a plumber. Low pressure may mean a leak, a clogged line, or a faulty shut-off valve — all things a plumber can find and repair. High pressure requires a pressure regulator, which a plumber installs at the main water line.
If your pressure is normal but you notice low flow at one faucet or fixture, the problem is local to that faucet — a clogged aerator or internal valve — and you can often fix it yourself by cleaning or replacing the aerator.
Frequently Asked Questions
Do I need a special gauge or will any pressure gauge work?
You need a water pressure gauge made for household plumbing, not an air pressure gauge or tire gauge. Water gauges are labeled for PSI and are designed to handle water. They cost $10 to $20 and are sold at hardware stores in the plumbing section.
What if I do not have an outdoor faucet?
You can test at any faucet, but choose the one closest to where water enters your house — usually a basement or laundry room. The reading will be slightly lower than at an outdoor faucet because of the distance, but it will still tell you whether pressure is normal, too low, or too high.
Can low water pressure be caused by my water company?
Yes. If your pressure is consistently below 40 PSI and your neighbors report the same problem, contact your water company. If only your house has low pressure, the problem is in your home's plumbing or the line from the street to your meter.
Is 90 PSI too high?
Yes. Pressure above 80 PSI can stress pipes and fixtures. At 90 PSI, you should have a plumber install a pressure regulator at the main water line to bring it down to 60 to 70 PSI.
How often should I check my water pressure?
Check once a year as routine maintenance, or whenever you notice low flow, banging pipes, or leaks. If you have had pressure problems in the past, check every six months to catch changes early.