Pressure Converter
Convert pressure between PSI, bar, pascals, atmospheres, and other units.
Frequently Asked Questions
What is the difference between PSI and bar?
PSI stands for pounds per square inch and is commonly used in the United States for tire pressure, air compressors, and hydraulic systems. Bar is a metric unit used widely in Europe and scientific contexts. One bar equals approximately 14.5038 PSI. For tire pressure, a typical car tire might be inflated to 32 PSI, which equals about 2.21 bar. Always use the correct unit when checking tire pressure, as using the wrong reference can lead to unsafe inflation levels.
What is atmospheric pressure?
Standard atmospheric pressure at sea level is defined as 101,325 pascals (Pa), or 1 atmosphere (atm), approximately 14.696 PSI or 1.01325 bar. This is the average pressure exerted by the Earth's atmosphere at sea level. Atmospheric pressure decreases with altitude, which is why aircraft cabins are pressurized. Meteorologists measure atmospheric pressure to predict weather patterns, since low pressure typically signals storms while high pressure indicates fair weather.
How is pressure measured in medical contexts?
In medicine, blood pressure is measured in millimeters of mercury (mmHg). Normal blood pressure is approximately 120/80 mmHg. One mmHg equals about 133.322 pascals. Medical equipment like sphygmomanometers and ventilators use mmHg or centimeters of water (cmH₂O). Intraocular pressure (eye pressure) is also measured in mmHg. Understanding these units is essential for healthcare professionals and patients tracking cardiovascular or respiratory health metrics.