MEASUREMENT & METHODS

Bars (bar): pressure unit guide

Understand bars (bar) for pressure. Check base-unit equivalents, examples, comparison tables and source conventions.

What is being measured?

Pressure is force per area. Unit scaling cannot change a gauge-pressure reading into an absolute-pressure reading without the reference pressure.

Atmospheres are standard atmospheres. Mercury-column factors use the conventional 0 °C definition; torr is 1/760 of a standard atmosphere.

Meaning of bar

Bars uses the symbol bar in this library and measures pressure. Under the stated reference convention, 1 bar = approximately 100000 Pa. This equivalence changes how a known value is written. It does not increase measurement accuracy or establish whether a measurement is appropriate to a real application.

Conversion method

Multiply the value by the source factor (100000), then divide by the target factor (1). The factor ratio expresses the same pressure measurement in the other unit.

Worked example

For a known value of 10 bar, the reference conversion gives 1000000 Pa. Converting that result back gives approximately 10 bar. This reverse check helps catch a reversed factor, but matching round-trip arithmetic alone does not independently verify a source definition.

Common reference values

Input (bar)Reference equivalent (Pa)
1100000
5500000
101000000
252500000
505000000
10010000000

Compare one bar with other units

Target unitEquivalent of 1 barDefinition guide
Pascals (Pa)100000Read definition
Kilopascals (kPa)100Read definition
Pounds per square inch (psi)14.503773773Read definition
atmospheres (atm)0.986923266716Read definition
megapascals (MPa)0.1Read definition
millibar (mbar)1000Read definition
Conventional millimetres of mercury (mmHg (0 °C))750.061575846Read definition
Conventional inches of mercury (inHg (0 °C))29.529983301Read definition

Precision and common mistakes

  • Keep the source and target quantity consistent. A matching symbol is not enough to establish a compatible definition.
  • Record the original measurement precision. Showing twelve significant digits in a table does not make a rounded input more precise.
  • Check symbol capitalization, prefixes and any regional convention in the source. Use the displayed unit definition rather than a similarly named unit.
  • Factors involving repeating fractions or π use finite numerical precision. Round the final answer to the precision justified by your input.

Use a working converter

Source and verification scope

Examples and tables are computed from the versioned unit definitions used by the linked converters. The source access dates appear below. Computandum is independent of the cited organizations; a citation does not mean that a publisher endorses this page or an actual project.

Sources

Read the calculation and sourcing methodology →