Pressure Unit Converter
Convert between Pascal, psi, atm, bar, mmHg, and torr pressure units.
What Is the Pressure Unit Converter?
The Pressure Unit Converter converts between all major pressure units: pascals (Pa), kilopascals (kPa), megapascals (MPa), bar, millibar, atmospheres (atm), PSI (pounds per square inch), torr (mmHg), and inches of mercury (inHg). Used in meteorology, engineering, medicine, and physics.
Formula
How to Use
Enter a pressure value in any supported unit. The converter instantly displays all equivalent values. Common conversions include PSI to bar (for tyre pressure), mmHg to kPa (for blood pressure), and Pa to atm (for atmospheric science).
Example Calculation
100 PSI: = 100×6894.76 = 689,476 Pa = 6.895 bar = 6.805 atm = 5171 mmHg. Blood pressure 120 mmHg: = 120×133.322 = 15,999 Pa = 16.0 kPa = 2.32 PSI.
Understanding Pressure Unit Converter
Pressure is force per unit area, with the SI unit being the pascal (Pa = N/m²). Named after Blaise Pascal who studied fluid pressure in the 17th century, one pascal is a very small pressure — the weight of a 100g mass spread over one square meter. In practice, kilopascals (kPa) and megapascals (MPa) are more common in engineering.
The diversity of pressure units reflects different historical measurement traditions: meteorologists use hectopascals (hPa, equivalent to millibars), US engineers use PSI, European engineers use bar or kPa, scientists use atmospheres or pascals, and physicians use mmHg. Converting between these is a daily necessity for international technical communication.
Pressure measurement is critical in HVAC design (duct static pressure), structural engineering (hydrostatic pressure on dams), process engineering (reactor vessel pressures), automotive (tyre and oil pressure), medicine (blood pressure and respiratory pressure), and weather forecasting (barometric pressure and its change rate). This converter handles all standard and specialized pressure units with full precision.
Frequently Asked Questions
What is standard atmospheric pressure?
1 atm = 101,325 Pa = 14.696 PSI = 1.01325 bar = 760 mmHg (at sea level, 15°C). Atmospheric pressure decreases with altitude: at 5500m (18,000 ft) it is roughly half of sea level pressure.
Why is blood pressure measured in mmHg?
Blood pressure is historically measured with mercury manometers. 1 mmHg (also called 1 Torr) is the pressure exerted by a 1mm column of mercury at standard gravity. Despite digital sphygmomanometers, mmHg remains the clinical standard.
What unit is tyre pressure measured in?
In the US: PSI (pounds per square inch). In Europe and Australia: bar or kPa. A typical car tyre inflated to 32 PSI = 2.21 bar = 221 kPa.
What is gauge pressure vs absolute pressure?
Absolute pressure includes atmospheric pressure. Gauge pressure (PSIG, barg) is pressure above atmospheric (relative to atmosphere = 0). A flat tyre has 0 PSI gauge but 14.7 PSI absolute.
Is this converter free?
Yes, completely free with no registration required.