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Pressure Converter

Popular Pressure unit conversions

Pressure Converter — Convert Pascal, PSI, Bar, ATM & More

Our free online Pressure Converter lets you instantly convert between 50+ units of pressure — from scientific SI units to industrial, meteorological, and hydraulic units. Whether you need to convert pascals to psi, bar to atmospheres, kPa to mmHg, or torr to kilopascals, this tool delivers fast and accurate results with no installation required.

Pressure is defined as force per unit area and is a fundamental quantity in fluid mechanics, meteorology, engineering, and medicine. Common unit systems include:

  • SI metric: pascal (Pa), kilopascal (kPa), megapascal (MPa), gigapascal (GPa)
  • Imperial / US: psi (pound-force per square inch), ksi, pound-force per square foot
  • Meteorology: bar, millibar (mbar), hectopascal (hPa), standard atmosphere (atm)
  • Mercury column: mmHg, cmHg, inHg (torr)
  • Water column: mmH₂O, cmH₂O, inH₂O, ftH₂O
  • Technical: atmosphere technical (at), kilogram-force per square meter/centimeter

All conversions use internationally standardized SI factors, making this tool reliable for engineering, meteorology, medicine, manufacturing, and everyday use.

Common Pressure Conversion Reference

Here are the most frequently used pressure conversions for quick reference:

  • 1 standard atmosphere (atm) = 101,325 Pa = 101.325 kPa = 1.01325 bar
  • 1 bar = 100,000 Pa = 14.5038 psi = 0.986923 atm
  • 1 psi = 6,894.76 Pa = 6.89476 kPa = 0.0689476 bar
  • 1 kPa = 1,000 Pa = 0.145038 psi = 7.50064 mmHg
  • 1 mmHg (torr) = 133.322 Pa = 0.133322 kPa = 0.001933 psi
  • 1 inHg = 3,386.39 Pa = 3.38639 kPa = 0.491154 psi
  • 1 megapascal (MPa) = 1,000,000 Pa = 145.038 psi = 10 bar
  • Sea-level atmospheric pressure ≈ 1013.25 mbar = 29.92 inHg = 760 mmHg

Frequently Asked Questions — Pressure Converter

Question: How do I use the Pressure Converter?

Answer: Select the unit you are converting from in the left list and the unit to convert to in the right list, then type your value. The result appears instantly across all listed units.

Question: What is a pascal (Pa)?

Answer: The pascal is the SI unit of pressure, defined as one newton per square meter (N/m²). It is named after mathematician Blaise Pascal. Standard atmospheric pressure is 101,325 Pa or 101.325 kPa.

Question: How do I convert psi to bar?

Answer: Divide the psi value by 14.5038 to get bar. For example, 30 psi ÷ 14.5038 = 2.069 bar. Alternatively, multiply psi by 0.0689476.

Question: What is the difference between bar and atmosphere?

Answer: One bar equals 100,000 Pa, while one standard atmosphere (atm) equals 101,325 Pa. They are very close: 1 atm ≈ 1.01325 bar. The bar is a metric unit used in meteorology and engineering; the atmosphere is the traditional unit for atmospheric pressure.

Question: What is mmHg and how is it related to blood pressure?

Answer: mmHg (millimeters of mercury) measures the pressure that supports a column of mercury 1 mm high. Blood pressure is measured in mmHg; normal blood pressure is about 120/80 mmHg. 1 mmHg = 133.322 Pa ≈ 0.00133 bar.

Question: What is psi?

Answer: PSI stands for pound-force per square inch. It is widely used in the US for tire pressure, hydraulic systems, and industrial applications. 1 psi = 6,894.76 Pa ≈ 6.895 kPa. Standard car tire pressure is typically 30–35 psi.

Question: How do I convert bar to psi?

Answer: Multiply the bar value by 14.5038 to get psi. For example, 2 bar × 14.5038 = 29.0 psi. This is a common conversion for tire pressure — European specifications are in bar while US specs use psi.

Question: What is the torr unit of pressure?

Answer: The torr is a unit of pressure equal to 1/760 of a standard atmosphere, or approximately 133.322 pascals. It is named after Evangelista Torricelli and is used in vacuum technology and some medical applications. 1 torr ≈ 1 mmHg.

Question: How accurate are the pressure conversions in this tool?

Answer: All conversions use internationally standardized conversion factors with up to 12 significant digits of precision, suitable for engineering, scientific, medical, and industrial applications.