Bar (bar)
A unit of pressure equal to 100,000 pascals
The Bar (bar) is a unit of pressure with a history connected to the study of fluids, gases, and atmospheric phenomena. Evangelista Torricelli's invention of the barometer in 1643 was a landmark in pressure measurement, and subsequent work by Blaise Pascal established the mathematical foundations. The pascal — the SI unit — was named in Pascal's honor when the SI system was formalized. The Bar reflects either the SI tradition or the practical conventions of specific industries that standardized their measurements independently.
Accurate pressure measurement is critical in engineering, science, commerce, and everyday life. Using the correct unit and applying conversions precisely prevents errors that can be costly or dangerous in professional applications.
Conversion Table
| Unit | Symbol | 1 bar = |
|---|---|---|
| Pascal | Pa | 100000 Pa |
| Kilopascal | kPa | 100 kPa |
| Atmosphere | atm | 0.986923 atm |
| Pound per Square Inch | psi | 14.5038 psi |
| Millimeters of Mercury | mmHg | 750.064 mmHg |
| Megapascal | MPa | 0.1 MPa |
| Gigapascal | GPa | 0.0001 GPa |
| Kilopound per Square Inch | ksi | 0.0145038 ksi |
| Torr | torr | 750.064 torr |
| Inch of Mercury | inHg | 29.53 inHg |
| Kilogram-force per Square Centimeter | kgf/cm² | 1.01972 kgf/cm² |
Conversions Involving Bar
Pascal → Bar
Pa → bar
Kilopascal → Bar
kPa → bar
Bar → Pascal
bar → Pa
Bar → Kilopascal
bar → kPa
Bar → Atmosphere
bar → atm
Bar → Pound per Square Inch
bar → psi
Bar → Millimeters of Mercury
bar → mmHg
Bar → Megapascal
bar → MPa
Bar → Gigapascal
bar → GPa
Bar → Kilopound per Square Inch
bar → ksi
Bar → Torr
bar → torr
Bar → Inch of Mercury
bar → inHg
Bar → Kilogram-force per Square Centimeter
bar → kgf/cm²
Atmosphere → Bar
atm → bar
Pound per Square Inch → Bar
psi → bar
Millimeters of Mercury → Bar
mmHg → bar
Megapascal → Bar
MPa → bar
Gigapascal → Bar
GPa → bar
Kilopound per Square Inch → Bar
ksi → bar
Torr → Bar
torr → bar
Inch of Mercury → Bar
inHg → bar
Kilogram-force per Square Centimeter → Bar
kgf/cm² → bar
Common Uses of the Bar
- •Automotive — inflating tires to manufacturer-specified pressures
- •Weather reporting — tracking barometric pressure for forecasting
- •Hydraulic systems — designing and operating fluid power equipment
- •Scuba diving — calculating safe dive depths based on partial pressures
- •Medical — measuring blood pressure and calibrating medical equipment
Did You Know?
The deepest point in the ocean — the Challenger Deep in the Mariana Trench — has a water pressure of approximately 110 MPa, or about 1,086 times standard atmospheric pressure. The Bar is one of several units used to express pressures across this extraordinary range.