How to Check Tire Pressure
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Checking tire pressure takes about five minutes and a gauge that costs a few dollars. Do it once a month and before long trips: under-inflated tires take longer to stop, wear faster, use more fuel, and are more likely to fail. Here is how to get a reading you can trust.
Checking pressure is simple, but do it parked well away from traffic with the engine off. If a tire is visibly flat, bulging, or cut, don't drive on it to reach air: fit the spare or call roadside assistance. Never inflate past the label pressure toward the maximum printed on the sidewall.
What you'll need
- Tire pressure gauge (digital, dial, or pencil type)
- The tire information label on the driver's door jamb, or the owner's manual
- Air: a gas-station pump or a portable 12V inflator (only if a tire needs it)
- A pen or your phone to note each reading
The steps
Tap through one step at a time — built for one-handed use at the roadside — or switch to all 7 steps to read ahead or print.
Step 1 of 7: Find your car's recommended pressure
Step 1: Find your car's recommended pressure
Open the driver's door and find the tire information label on the door jamb, or look in the owner's manual. It gives the recommended cold pressure in PSI, which can differ between the front and rear tires and for a compact spare. Ignore the maximum pressure molded on the tire sidewall: that is the tire's limit, not your car's target.
Step 2: Check before you drive
Measure when the tires are cold, meaning the car hasn't been driven for at least three hours. First thing in the morning is easiest. Driving warms the air inside and raises the reading, so a check straight after a trip can make a low tire look fine.
Step 3: Unscrew the valve cap
Find the valve stem, the short stem sticking out of the wheel, and unscrew its cap. Put the cap in your pocket rather than on the ground. It keeps dirt and moisture out of the valve, so it needs to go back on.
Step 4: Press the gauge on and read it
Press the gauge straight and firmly onto the valve stem. A short hiss as it seats is normal; a hiss that keeps going means it isn't on squarely, so press again. Read the number, then take a second reading to be sure. Digital, dial, and pencil gauges all work if they read consistently.
Step 5: Repeat on every tire, including the spare
Check all four tires, not just the one that looks low, and note how far each reading is from the label. Then check the spare if your car has one, against its own pressure on the label. A tire can be well below its pressure and still look normal, so never judge by eye.
Step 6: Add air, or let a little out
If a tire is low, add air in short bursts and recheck with your gauge until it matches the label. If it is over, press the small pin in the center of the valve for a second, then recheck. If you had to drive to reach the air pump, the tires will have warmed up: add the amount each tire was low when you checked it cold, rather than filling to the label number, and recheck when they are cold again.
Step 7: Refit the caps and watch for a slow leak
Screw each valve cap back on finger-tight. If one tire needs air again within a few days, or keeps reading lower than the others, it probably has a slow leak from a nail, the valve, or the wheel rim. Have a tire shop find and repair it rather than topping it up every week.
Related tools
Related warning lights
If you see one of these, check what it means and whether you can keep driving before starting any work.
Frequently asked questions
Sources
Where the figures on this page come from. Your owner's manual still wins for your specific vehicle.
- Tire Safety Ratings and Awareness (TireWise)National Highway Traffic Safety Administration (NHTSA). Cited for: Check all tires, including the spare, at least once a month when cold (not driven for at least three hours), using the vehicle manufacturer's pressure rather than the number on the tire. Note how far each tire is below it and add the missing pressure, and recheck once a cold reading is possible. Checked .
- Keeping Your Vehicle in ShapeU.S. Department of Energy and U.S. EPA (fueleconomy.gov). Cited for: the proper pressure for a vehicle is the one on the driver's-side door-jamb sticker, the glove box, or the owner's manual — not a figure read off the tire. Checked .
- 49 CFR § 571.138 — Standard No. 138; Tire pressure monitoring systemsU.S. Code of Federal Regulations, via Cornell Law School LII. Cited for: S4.2 requires the low tire pressure telltale to light at 25% below the vehicle manufacturer's recommended cold inflation pressure, or the tire-type minimum in Table 1, whichever is higher. Checked .