Pressure Converter
Convert psi, bar, kPa, atmospheres, mmHg and inches of mercury.
All units
About this tool
Convert between the pressure units that show up in daily life: psi for tires, bar on European gauges and espresso machines, hectopascals and millibars in weather reports, atmospheres in science class, and millimeters or inches of mercury on barometers. Type a value, pick two units, and the result updates as you type; the all-units table shows every equivalent at once.
The factors are the exact SI definitions (1 psi is 6,894.757 Pa; 1 atm is 101,325 Pa), so results match a reference book rather than a rounded rule of thumb. The swap button flips direction, the last units you used are remembered, and everything runs locally in your browser.
Frequently asked questions
- What is normal tire pressure in psi and bar?
- Most passenger cars run 30-35 psi, which is roughly 2.1-2.4 bar. Check the sticker inside the driver door for your exact numbers, and measure when the tires are cold.
- Are hectopascals the same as millibars?
- Yes, exactly. 1 hPa = 1 mbar = 100 Pa. Weather reports use them interchangeably; standard sea-level pressure is 1013.25 hPa, which is 1 atmosphere.
- Is my input sent anywhere?
- No. The conversion runs in your browser with plain JavaScript, so nothing is uploaded and it works offline once the page has loaded.