Pressure Conversion Calculator
Convert pressure between PSI, bar, atm, Pa, kPa, mmHg, inHg, and other pressure units instantly.
Calcady™ · Calculation Report Pressure Converter calcady.com Pressure Scale2.41317 Converted Pressure2.41317 Bar |
Quick Answer: Common Pressure Conversions
1 atm = 14.696 PSI = 1.01325 bar = 101,325 Pa. 1 bar = 14.504 PSI. 1 PSI = 6,894.76 Pa. Tire pressure is typically in PSI (US) or bar (Europe). Blood pressure is in mmHg. Weather uses inHg (US) or hPa/mbar (global).
Pressure Unit Reference
| Unit | = PSI | Common Use |
|---|---|---|
| 1 atmosphere (atm) | 14.696 | Sea-level reference |
| 1 bar | 14.504 | European tire pressure, industrial |
| 100 kPa | 14.504 | Engineering, science |
| 760 mmHg | 14.696 | Blood pressure, lab vacuum |
| 29.92 inHg | 14.696 | US weather, aviation altimeters |
Frequently Asked Questions
What is the difference between PSI and PSIG?
PSI (or PSIA) is absolute pressure — measured from a perfect vacuum. PSIG is gauge pressure — measured from atmospheric pressure. At sea level: PSIA = PSIG + 14.696. A tire gauge reading 35 PSIG is actually 49.7 PSIA. Most everyday pressure references (tires, shop air, water lines) use gauge pressure (PSIG).
Why is blood pressure measured in mmHg?
Early blood pressure instruments (sphygmomanometers) used a column of mercury (Hg) displaced by arm cuff pressure. A reading of "120/80" means the systolic pressure pushes mercury up 120 millimeters. Though modern devices are digital, the mmHg unit persists because the entire medical literature and drug dosing protocols are calibrated to it.
How do I convert tire pressure between PSI and bar?
Divide PSI by 14.504 to get bar (or roughly divide by 14.5). Common conversions: 30 PSI ≈ 2.07 bar, 32 PSI ≈ 2.21 bar, 35 PSI ≈ 2.41 bar, 40 PSI ≈ 2.76 bar. European cars list tire pressure in bar on the door jamb sticker. If renting a car abroad and the gas station pump shows bar, use this converter to find the right setting.