Millibars to Bars Converter
Enter the pressure in millibars below to convert it to bars.
Convert Millibars to Bars
Enter a value in millibars (mbar) to convert to bars (bar).
Millibar to Bar Conversion Table
Table showing various millibar measurements converted to bars. Click any preset value or arrow to load it into the converter.
How to Convert Millibars to Bars
To convert millibars to bars, multiply the pressure by the following conversion ratio: 0.001 bars/millibar.
Since one millibar is equal to 0.001 bars, you can use this simple formula to convert:
The pressure in bars is equal to the pressure in millibars multiplied by 0.001.
For example, here's how to convert 5 millibars to bars using the formula above.
How Many Bars Are in a Millibar?
There are 0.001 bars in a millibar, which is why we use this value in the formula above.
Our millibar to bar calculator automatically converts your pressure measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Millibars and bars are both units used to measure pressure. Keep reading to learn more about each unit.
What Is a Millibar?
A millibar is a unit of pressure equal to 100 pascals (Pa), the base unit for pressure. Meteorological pressure unit equal to 1/1000 of a bar (100 Pa = 1 hPa). [1]
The millibar is classified as a metric and SI-compatible unit of pressure. Millibars can be abbreviated as mbar; for example, 1 millibar can be written as 1 mbar.
In the metric system, "milli" is the standard SI prefix for thousandths, or 10⁻³. This makes the millibar (mbar) a convenient decimal multiple of the bar (100,000 Pa).
In practice, millibars (mbar) are widely used across standard pressure applications within SI metric workflows, engineering documentation, and technical data sheets.
What Is a Bar?
A bar is a unit of pressure equal to 100,000 pascals (Pa), the base unit for pressure. Metric pressure unit equal to 100,000 Pascals (100 kPa). [2]
The bar is classified as a metric and SI-compatible unit of pressure. Bars can be abbreviated as bar; for example, 1 bar can be written as 1 bar.
When working with bars (bar) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, bars (bar) are widely used across large-scale industrial, bulk, and macro-level pressure specifications within SI metric workflows, engineering documentation, and technical data sheets.
When converting pressure between millibars (mbar) and bars (bar), keep full floating-point precision (1 mbar = 0.001 bar; 1 bar = 1,000 mbar) during intermediate calculations and round only the final bar figure to match your instrument tolerance.
More Millibar & Bar Conversions
Need to calculate in the opposite direction? Use our bars to millibars calculator to switch your starting unit immediately. You can also explore related tools such as converting bars to millibars, converting psi to bars, or converting atmospheres to bars.
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Pressure & Stress))·Pressure Metrology Standard — Millibars (mbar) to Bars (bar)
- [2]NIST CUU SpecificationNIST CUU (Derived SI Unit: Pascal (Pa))·Unit Specifications: Millibar (mbar) & Bar (bar)
- [3]BIPM ReferenceBIPM (SI Brochure (9th Ed.) — Mechanics)·Conversion Factors & Mathematical Basis (mbar to bar)