TirePressure: PSI Tracker

TirePressure tells you what to fill your tires to when you inflate somewhere warmer than where you drive, like a heated garage on a winter morning. Air pressure moves with temperature by roughly 1 psi for every 10F. The pressure on your door placard is a cold pressure, and it holds at any outside temperature, so TirePressure never takes you below it. Fill in a warm garage and drive out into the cold, and the tires lose pressure as they cool. TirePressure adds about 1 psi for every 10F of difference, so they read the placard pressure once they reach the outside temperature. It also shows what the tires will read once they are hot from driving. WHAT YOU CAN DO - Enter your door placard pressure, where you fill and the coldest outside temperature, and get the pressure to fill to - Never get a figure below your placard pressure, whatever the weather - Read the fill pressure in psi, bar and kPa at the same time, with no setting to switch - Check the expected hot pressure before a warm gauge reading makes you let air out - Enter temperatures below zero for winter mornings - Watch every number update as you type, with nothing to submit and no waiting - Work from results rounded to a tenth of a psi - Use it on iPhone and iPad, in light or dark appearance WHO IT IS FOR Drivers who fill their tires in a heated garage and then park or drive in the cold. Owners of cars, trucks, trailers and motorcycles who inflate their own tires and want the temperature accounted for instead of guessed at. Anyone who watches the pressure warning come on every autumn. PRIVACY There are no accounts and no sign-in. TirePressure makes no network calls, so it runs with no signal at all, and nothing you enter is stored or sent anywhere. No advertising, no analytics, no subscriptions and no in-app purchases. TirePressure is a calculator built on the 1 psi per 10F rule of thumb. Follow the pressure on your door placard, and check pressures with a gauge on cold tires, before driving.