Pressure Converter

Pressure is force per unit area. The SI unit is the pascal (Pa = N/m²). 1 atmosphere of pressure at sea level is about 101,325 Pa, or roughly 14.7 psi (pounds per square inch).

1 bar = 100,000 Pa (exact). 1 atmosphere (atm) = 101,325 Pa (exact). They are similar but not identical: 1 atm ≈ 1.01325 bar. The bar is often used in everyday contexts (tire pressure, weather), while atmospheres are a historical reference.

Practically the same in everyday use. mmHg (millimeters of mercury) is defined from the height of a mercury column. 1 torr is defined as 1/760 of an atmosphere. They differ by less than one part in 10 million; treat them as interchangeable for any non-scientific purpose.

Typical passenger-car tire pressure is around 30 to 35 psi, which is about 207 to 241 kPa, or roughly 2.07 to 2.41 bar. Always follow the vehicle's recommended pressure shown on the driver-side door jamb sticker, not the tire's max-rated pressure on the sidewall.

Pascals are the SI base, but they're very small. 1 atm is over 100,000 Pa, so kilopascals (kPa = 1,000 Pa) are far easier to read in most contexts. Industrial and weather pressure is usually in kPa, while precision physics uses pascals.

It can be used as a unit converter for mmHg, which is what blood pressure is reported in. But blood-pressure categorization (Normal, Elevated, Stage 1, Stage 2) needs the dedicated blood pressure calculator, which classifies a reading rather than just converting units.